No AF, no BFP, I'm confused

My LMP was march 13. Had a positive opk the 29th and 30th. BD the 29th. Was suppose to start April 14th but didn't. I had light spotting April 20th and 21st (didn't even wear a pad or tampon, there was only pink blood when I wiped) took hpt and got a BFN. I spotted again on may 13th for half the day (same kind of spotting) and then may 16th (wiped once in the morning and it was red on the toilet paper and no more spotting after) I still have only got BFNs. I've had lower abdominal/pelvic cramps off and on since the week after march 29th as well as some lower back pain. I keep thinking maybe it's my period going to start but it never does. The cramps are also on the sides of my abdomen and the cramps kinda feel like pulling. However, i do have irregular periods and have gone 2 and a half months without a period but I've NEVER spotted in between. I'm confused what's going on with my body. I go to the drs on Friday but any insight anybody might be able to share would be appreciated. Thank you in advance!