Possible miscarriages....low progesterone?

We've been TTC for three cycles. I always cycle like clockwork (28-29 days) and the last three cycles have run long...33-35 days with abnormal cramping. The first cycle, I got a faint positive but may have m/c. I didn't bother testing these last two cycles, trying to be patient and let nature show me. But I've had such awful periods that I can't help but think I miscarried all three cycles! I am very frustrated! I ovulate late in my cycle, about 11 days before AF, and I've read that could be a sign of low progesterone, which can cause early miscarriages. I am tired of the pain of TTC at this point because I am afraid it will never stick! Is there any natural ways of increasing progesterone? I don't want to go the medical route...I never trust doctors because there are always terrible side effects with what they offer. Any advice, ladies??? Thanks so much! *Mega TONS of baby Dust!!!*