Prenatal vitamins while on medication?

**Edit: this is posted as a topic in TTC Australia&NZ, as I'm from Australia

Hey ladies,

I'm wondering what your general suggestions are for prenatal vitamins when on other medication?

Ok so a bit of background, DH and I saw my Doctor to see if I need to come of any of my medications or swap them out to be 'conception' safe.

I have Spondyloarthropathy (a type of arthritis), Endometriosis, Costochondritis (side effect condition of the arthritis), and Idiopathic Intracranial Hypertension.

So I'm on Sulfasalazine (for the arthritis), I was previously on birth control for the Endometriosis (but had to come off it in June 2018 for I.I.H diagnosis), I have been told not to take the anti-inflammatory for Costochondritis, and I'm on Topiramate for Idiopathic Intracranial Hypertension....oh and I'm on Desvenlafaxine (commonly known as Pristiq), an anti-depressant/anti-anxiety too.

I take 4 Sulfasalazines, 2 Topiramate, and 1 Desvenlafaxine a day and I don't know if I should embark on prenatal vitamins?

My doctor I saw recently, only said I need to up my amount of folic acid and I should be eating fish (not deep sea) twice a week prior to getting pregnant.

And once pregnant, I'd need to get some tests done and they'd likely put me on a folic acid supplement to make sure I had 5mg in my system, test my vitamin D, stop the fish intake, check my iron levels, etc.

I've also been told that once I have a confirmation of pregnancy via the doctor that's when they'll do whatever swapping to my medications necessary...

So, I know you're not medical professionals but I'm wondering if anyone can help me?