how far along am I again? mommy brain

Ch

hubby and I were talking about when we were going to announce the pregnancy the other night. I told him I want to wait until the 2nd trimester which is around 12 or 13 weeks. told him I'm 8 weeks now, so do the math. 2 days later, I realise I'm actually 9 weeks. I have a 1.5yr old little boy and I'm a SHM... my brain doesn't function properly after 7 lol anyone else have mommy brain? sheesh I'm goin crazy!