It's been 2 months without having my period. I've had all these hormonal test and they've come back normal

I've had a pregnancy test yesterday and that's came back negative. I'm really unsure why I've skipped two full months. I'm usually regular. Give or take a week. I thought it was hormone related because my boobs have hurt and I have bad acne on my chin for the last few weeks. I'm not overly stressed (apart from worrying it's been THIS late, it hasn't been this late since I found out I was pregnant with my daughter about a year ago)

I have had unprotected sex (that was in aug/start of September) but I had my period on the 22-28 and that was the last time I had my period (hence why the pregnancy test) shouldn't it be positive by now???

I'm really lost at the moment on what it could be, has anyone had this. What was the outcome??? I'm also not on any birth control. So it can't be that. Thank you ladies xxx