Does anyone know how much weight you should gain in each trimester?

I’m 16 weeks and I’ve gained 11lb. I have a bump but have also rounded out.

I was slim beforehand but I never naturally thin. I was always watching what I ate and went to the gym regularly. Although I don’t eat for two now, I am eating more than I was pre-pregnancy and definitely more naughty bits (guilt free as I see it).

I just don’t want to over do it, so wondered if anyone knew of any guidelines?