Dp and I had ‘a break’ in February (very important) it was short lived (a month) and we sorted things out... last week, I took a preganacy test and it was positive. Was fully expecting that because my Lmp started 8/3/18... we’re not trying for a baby but also not really using condoms correctly (spur of the moment, no condom..) knowing this is our approach to contraception I’m half expecting this.... so last night I told dp I’m pregnant and he’s actually okay with it. We spent the whole night chatting about what was to come and how exciting it all is, i woke up this morning feeling so happy!! Today I booked my first antenatal appointment and told dp it’s in a few days, he is happy and says he’ll be there. I mentioned that they said my 12 week scan is due at the end of May and not to worry because when they say I’m 12 weeks pregnant they really mean I got pregnant 10 weeks ago as they use LMP dates and he was instantly ‘you shagged someone else while we’re on a break and now you’re saying this child is mine’ 
... well, no, that’s what’s going to happen isn’t it? They’re going to take my Lmp and add 2 weeks? He’s asked me to explain why they would do this and I’ve said it’s just what happens but he’s convinced I cheated on him. Don’t boys learn this in sex Ed? Why doesn’t he understand this?