OK, this is going to sound stupid, but it's my first pregnancy and I've only known since Thursday, but I'm really confused about how to count how pregnant you are.
My last cycle began on 26th Feb, so according to the information in the pregnancy calendar on this site I'm almost 7 weeks pregnant (ie you count it from the first day of your last cycle), but when I put my details into NHS choices it tells me I'm 5 weeks pregnant - so presumably it's counting it from roughly when I would have ovulated.
Which is the right way to count how pregnant you are?