advice pleassee!!

my period is 12 days late... I use to get irregular periods.. & sometimes it crosses my mind that I can't get pregnant... but my irregular periods.. & usually that mean cyst on ovaries; which means it's hard to get pregnant.. but I'm 12 days late... I haven't had my regular mentrual cramping but I've had some stomach & lower abdomen, painful rightness & sharp pain, & sometimes my boobs are a little sensitives at times. I've taken a pregnancy 4 days before & 4 days after my missed period. they were both negatives. they were also dollar tree test, so I'm not sure how accurate... but I just want someone to calm my nerves. they're not shot but it's in the back of my head. help!! thankss😁