Period....symptoms but nothing...pregnant?!?!?

Nina
Never done this before....but here it goes I've been getting period symptoms for 2 weeks now on and off today ive had terrible back aches and mild cramps but no period I had sex around my ovulation window at the end of September its almost the end of October and nothing. I've taken 2 tests and they are negative SIDE NOTE i had a mc last year and while pregnant I HAD 3 NEGATIVE tests so I'm starting to worry i also have sore breasts Can someone help? Insight on this weirdness or similar situation cause I'm starting to freak