missed period day 12

missed period day 12. last week had a faint positive, but today went to doc for urine test and came back negative. I’ve been feeling like i have to pee more often no burning sensation and I ruled out it’s not a UTI from the doc. my breasts developed montgomery tubules(which i never knew what this was so i had to look it up when my breasts changed). I feel nauseated here and there. Last week i had a weird cramp in my abdomen for like an hour just that day. I finished my round of Birth control pills on October 27. Really no other symptoms what should I do?