first fertility appointment

so I had my first fertility appointment last Friday and she said given my age (21) and how long we’ve been trying (only 8 months) there wasn’t a lot she could do as far as medication wise.

I told her I have been taking the “conceive” vitamins from eunaturals and tracking using opks and have not gotten a positive one yet.

she then told me since we’d been doing that, we could start doing some labs and try to pin point what’s out of whack/making me not ovulate and she would consult with the md at the practice.

I have PCOS but since taking those “conceive” vitamins, i’ve had 4 periods over the last 4 months which is huge since i went almost a year without a period and was only getting them if i was on BC.

so i’m wondering what she is testing? obviously thyroid since it was wonky last time i went in and then a couple vaccines to see if I need boosters, but what are the other things and why are they sensitive to where you’re at in your cycle? any idea?

thanks gals!