Folic acid supplement nausea?

We are TTC so I have been taking folic acid and vitamin D supplements. I was taking them and feeling nauseas but it was very hot in the UK so I put it down to that. I forgot to take them for 2 days and felt fine. Now that I started taking them again I feel sick pretty much all day.

Did anyone else get nauseas taking them? Or am I just going mad?

I’m just getting positive opk’s so it’s not pregnancy.