I'm So Bummed

Husband and I are trying for our 4th. I was really really hoping for a Spring baby. I'm on day 6 of spotting, and today was actually borderline light flow. I'm pretty sure I'm going to start my period tomorrow, and today was only CD21/8dpo (best guess on O per OPKs). The longest cycle I've had since April was 31 days, and that was because I took progesterone for 10 days. Even THEN, I spotted for the last 3 days taking it. My cycles have been 24-25 days otherwise, with 5-6 days of spotting before my period starts. I'm so discouraged. Maybe I'll make an appt with my OB/GYN. Anyway, thanks for reading. <3