Confused

I'm not sure what group to post this in but me and my best friend of 20 years decided to start seeing each other and so far it's going great it's been over 2 months now and I couldn't be happier but before we started seeing each other our conversations heated up to the point we decided to have FWB relationship about a month down the road my mom ask him to impregnate me 🤣 ( she wants another grandbaby really bad) well he surprisingly agreed ( I already have a 12 year old and he has a 6 year old) so we stopped using all protection and started trying well we didn't conceive but we blossomed into a relationship our girls met for the first time this weekend and they absolutely love each other and we live roughly 3 hours away from each other I was here visiting for 2 weeks over Christmas and ofcourse all the sex I could want happended ( NOT COMPLAINING 😂) I'm leaving today and literally sick to my stomach about having to leave him again, I was here during my ovulation period and this time I have completely missed my period all together ( I have been here since Friday evening) I tested yesterday morning and this morning with both negative results I don't know what's going on but any advice would be greatly appreciated.