doctors appointment

right I've had periods all over the place since coming off the pill October 16.

I had bloods done about 12/14 months ago had low vitamin d levels but otherwise all okay. I'm overweight so been told that could affect them! When I was a teen they were all over the place so I don't 100% think it's just my weight.

Anyway i'm going back to the doctors next week to raise it again. I'm from the UK so it's just my GP I'm going to see rather than a gyno!

what should I be asking for? tests? medication? referral? any advise??