Hi Susey, last month I had a MC, started bleeding (on a Wednesday) just before 12 weeks. Baby had stopped growing at 5 weeks but sac had carried on. I was on holiday at the time, and like you was wondering about going back to work - physically I felt pretty normal at first. The bleeding got heavier, then large clots, also contraction like pain, then the next day (sunday) passed a large amount of clot/ tissue. After that the bleeding gradually tailed off. (lasted about 4 weeks in total). I felt really weak afterwards. I had hoped to go back to work on the Thursday, but when i went to the EPU for repeat scan, I was told to take at least another week off, and given sick note for 2 weeks. DH made me do as I was told. I was quite relieved really, as I think I would have struggled physically.
I think I could have managed to go back the following monday (a week after passing the sac), although it would have been a struggle. (I started doing some bits from home). I went back on the Thursday (don't work Weds), and coped OK. This was 2 weeks after I started bleeding/
I was really surprised how much it took out of me physically - it felt like I was recovering from nasty flu (that really weak feeling) but it went on longer, hormones all over the place etc. That's before the emotional side.
It's only in the last few days (5 weeks on) that I'm really feeling back to normal physically.
Of course it'll be different for everyone and I hope you'll have an easier time, but I was not expecting it to be this bad. I'm not good at being ill/ having time off, and didn't want people to ask why I'd been off, if I was better etc. (I just smile and say 'nothing serious, better now thanks').
Try not to expect too much, see how you go and be honest with yourself - if you don't feel up to working, don't - look after yourself, you'll know when you're ready physically and mentally to go back to work.