I haven't taken progesterone, but I've been seriously debating it. As I understand it, your temps won't fall and your cycle start until you stop the progesterone, and I think progesterone is responsible for some of the hormonal side effects of pregnancy. However, if it were me, I'd get the dr's office to do a blood test, it can't hurt.
Keep us posted.
Laura, Mama to Mya 7/02, Ian 6/07 and Anna 8/09