Confused.... follow up

Ok... try to stay with me, cause I am at a loss... My cycle is usually 28-30 days. Last period started April 15. I had positive opks on April 3-4, AND on April 13-14, I figured the recent ones were just picking up the lh surge for af. Af was due either May 14 if going by my regular cycle, or May 18 based on positive opks. Never came.... then today some spotting, but old blood mixed with cm. I have a doctor appt on May 31, but I legit feel like some kind of alien freak. Am I getting my period? Is this implantation bleeding? I'm still hopeful tbh