Hey I was doing some research on this yesterday myself, mainly because I was wondering about whether androgens are found in birth control - which apparently they are. Also a big word of warning here, do not take chasteberry with birth control because it reduces the contraceptive effects. You might not have been able to find it anywhere because another name for it is vitex - in the UK we can get it at Boots/ Holland & Barrett. I can't advise about saw palmetto or black cohosh but if they are similar supplements to vitex I'd double check about pregnancy.
Also depending on which bcp you're on, spiro is included in some of them - the one I'm on is Yasmin and that definitely contains spiro, which is why I think it's given to people with acne (there are increased health risks though so get some advice from the doc).
Another thing I recently found out from a bit of research was that vitamin d3 is a hormone balancing supplement so could be worth a try? Anyway, always take everything with a pinch of salt on this site, people will give some great recommendations and advice but take those suggestions to your doctor before trying anything, especially if you're planning on taking supplements in conjunction with other medication.