Am I being unreasonable/over dramatic?!

[Maybug12]

Just laying in bed with some third trimester insomnia and cannot switch my brain off!
I'm laying here concerning myself over a shift at work I have next week which seems silly I know. I work with young people with severe and complex special needs and challenging behaviours and next week I am leading a large group into London to go to the science museum. When we go I will be just under 32 weeks pregnant - I am concerned that this is going to be a bit much on me! Considering I struggled to stand for around an hour in Mamas and papas earlier without my bump and back starting to ache.... Thing is I told my boss this and she said she didn't mind doing the shift for me (in a kind of if I have to manner) but has rota'd me in anyway.
Am I just being a bit over dramatic in thinking it will be a bit of a hard long day to do at 32 weeks pregnant or am I just being a bit of a wimp and should just suck it up and do it?
I don't want to appear moany or lazy/trying to get out of shifts when I there's no reason I shouldn't do them... I have heard the way my boss has spoken about another colleague at work who was pregnant and she felt she used it as an excuse for everything! I don't want her to think I'm doing this too, I just feel that I may struggle a bit!
Is my tired brain over thinking this way too much?

If you don't feel like you are up to it then don't do it. Your workplace must make reasonable adjustments for you.

Regardless of if your boss thinks you are making excuses it sounds like you know you won't be able to cope/enjoy it so are making the sensible choice to swap shifts.

There should officially be a risk assessment done by your employer and reasonable adjustments made to your work. You'd be reasonable to say you can't go or make exceptions for which parts of the day you can/can't participate in. You should not just automatically be rota-ed in.

I think it's very individual to be honest. I would have been fine with that at 32 weeks and often had long days travelling to London for work till I was 35 weeks, but I did make sure I had rests when needed. However, if you're not up to it then don't go. Or make it clear if you do that you'll need some rest periods as standing up and walking around constantly is knackering!
Don't worry about what your boss thinks it's not their body!

Just like Anna I would have been fine at that point in my last pregnancy, but everyone is different and only you really know if you can do it. If you are having doubts I'd say you need to swap or at the very least be accompanying rather than leading the group. Having you down to lead seems a bit crazy anyway as you will need more breaks than the rest of the group, and it's not fair for them to have to wait around for you. If the manager starts making comments I think you should have a quiet word with HR, it's not on especially as I'm guessing she's not a qualified doctor or midwife?

If you do it, take a small lightweight foldable camping seat with you. I'm feeling faint a lot so waiting in queues is impossible. I just whip my seat out and sit down, job done.

Thanks for your advice everyone! I feel a bit silly for fretting over it - I've always been a hard worker and I've done my best to make sure I still do as much as I have been able to whilst pregnant. My job is really physical and at times very challenging, and I know I have definitely been in situations that are considered unsafe during pregnancy and I haven't once moaned about it!!
I think I could get through the day I just know that I would be absolutely exhausted and horrendously achey by the end of it! My back has been playing up through out the most of my pregnancy! Just feel a bit awkward to bring it up again when I've already had one big conversation about it!! 🙈

Just say something like 'oh do you remember we discussed this shift and agreed it would be best if you take it as I am unable to stand/walk for protracted periods at the moment'

I would swap! I work in a place with lots of stairs and concessions have been made for me, so I don't have to be waddling up and down them all day! Well the down is ok but the up is a struggle after a few times! I'm 33 wks. I certainly wouldn't want to be leading a group of people around a museum all day! I'd be knackered! Like several people have said already, you know how you feel and how well you will cope. Don't feel guilty if you feel you can't!

I teach sen and did my last trip at around 32weeks. I had to write myself into the risk assessment and take more members of staff than usual to make up for the fact that I couldn't race around after anyone, it was a big deal as I needed rest breaks etc. Trips are very tiring even if you not pregnant! If you don't feel up to it it is Perfectly acceptable not to do it, it is a more than reasonable adjustment for work to make. If your boss seems a bit snappy ignore it - you have bigger fish to fry/babies to bake.

Thank you! So appreciate knowing that I'm not just making a big deal out of nothing X