Very weird. Maybe I'm just overthinking

So, usually i am very in tune with my body and i can recognize all of the symptoms before I get my period.

But this is my case, i recently broke up with my boyfriend of 2 years. And the last 2 times we had post break-up sex was in my ovulation peak.... He didn't come in me but we use the withdrawal method ...

Now here's the thing, last month my period was weird, it lasted the whole 7 days but lighter than usual, but more than just spotting. And now this month I've been 2 weeks with my nipples on fire and they've gotten slightly bigger (which is not normal for what I'm used to).

I've already done 5 pregnancy pee-tests and they've all come out negative... so idk.... That's why I say very weird.... Any advice ladies?