Why hasn’t my period started?????

Linny

I’m officially 12 days late. My husband and I only had sex once this cycle and it was 2 days before my period was supposed to start. I’ve never been this late (except for when I was pregnant) so I took a test yesterday and it was a BFN but I took another one today and I don’t know if it’s just me but it looks like a very very faint positive.