My cycles have been royally messed up since the concussion I sustained in an auto accident too.

After almost 3 years, I finally went to an experienced expert who diagnosed me with hormonal imbalances that were due to the concussion. (3 other endocrinologists turned me away...)

Iw as suffering from many additional symptoms of neuroendocrine dysfunction other than just the cycle problems - actually the cycle problems were the least of my problems...

You can Google "neuroendocrine dysfunction" with "Concussion" and/or "traumatic brain injury" and discover quite a bit of recent research on the subject.

Most neuroendocrine dysfunction that is caused by a concussion resolves itself within 1 year.

Some experts speculate that neuroendocrine dysfunction is what causes PCS altogether!

I have been on replacement hormones for several weeks and I have been slowly getting better FINALLY.

I recommend you ask for a referral to an endocrinologist.

If you have trouble finding one with experience in your area you can try to look one up on the Pituitary Network Association website. And you are welcome to PM me at any point for anything. (That goes for anyone!)

Unfortunately, a lot of neuroendocrine dysfunction can progress to affect more than one hormone, so it may be more than just a progesterone imbalance that you're dealing with. Keep an eye on what's going on with you and create/keep a log of any and all symptoms, if possible.

Much luck!