Advice?! Sorry it’s a little long

Alright ladies! I need advice please!

I am now on day #18 on being late on my period. We did BD during my window and other days. I have very steady cycles. I have taken pregnancy test after pregnancy test and they’re all negative. When my period was originally due that week my boobs were hurting like there was not tomorrow. That weekend I went pee and there was literally the smallest brown stains you can imagine and it would only be visible when I wiped.That lasted for 2 days and than boom gone. Okay , I have have SEVERE watery CM the past few days. I’ve had nausea, smells of food have been insane and gross, I’ve been craving weird things. Okay so my next period is now due this Saturday and same thing is happening my boobs are hurting insanely(they’ve been hurting everyday but this week is bad again). My back hurts it’s just been weird. I took another pregnancy test last night and got another BFN.. ADVICE PLEASE?