Confused!!

S

So my cycle averages 26 days. In may I used OPK for the first time, started on the 21st and didnt get my positive until the 1st and 2nd. May 13th was the first day of my last period, so my period is technically due about today, going off a 26 day cycle.. I figure I'm 7-8 dpo. I'm wondering if it's possible to ovulate that soon before your period is "due"? Sometimes my cycle goes in between 26-29. Should I wait to test closer to the 13th? Absolutely no sign of a period, my left nipple has been hurting today and I have weird pressures in my lower area, and have been nauseated. Advice pleaseee 😟