I took my nuva ring out and had sex in July a couple days after my period

It’s November and I’ve taken 3 pregnancy tests

All negative

I’m 25 days late but I’ve had my periods in August and September

I have a “tightness” feeling in my abdomen and a swishy feeling kind of

My boobs don’t hurt at all

I have one vein in my left boob but i feel like I’ve always had that

Have I just forgotten what it feels like to have my period and I’m just stressing and pushing my period or all the pregnancy tests wrong