7 weeks or 11 weeks pregnant or stupid to think this?

[frobskottle]

So I am assuming that my last period was on the 28th of April however it lasted at the most two days and was very light.
The month before I had my usual pregnancy symptoms, nausea and tiredness which seems to happen for me very early on. I don't know whether maybe I had a chemical pregnancy then and so it was a period on the 28th and I am 7 weeks pregnant or is there a possibility I was pregnant then and the bleed meant nothing?
Im not sure whether to mention this at my booking in or if it's a silly thing to think!

My previous proper period was on the 7th of April so I had a 21 week cycle which is very unusual for me.

I would discuss it at booking, in terms of "I definitely had a proper period on 7th april, then a very short bleed on the 28th and am not sure when I conceived" - they will probably scan you asap for dating to ensure you can get the screening done in the 11-14 week window if you want it. Really it's just screening that would be affected by the dates being out, so if that's important to you, you need to find out asap. If I was you I would see if they will arrange an early dating scan and if not, book a private one.

Thanks! I think I have a 10 week scan to check for a molar pregnancy so I they maybe will let me know then if I'm further along than they think. I think I was only worried as if I was further along this would be done earlier. I imagine it doesn't make too much difference!