Period changing

Ok so not sure where to post but here I go:

So I have been ttc for 7 mths and nothing but the past two periods they have been 2 days late from when I supposed to start my period and also much heavier

I never bleed heavy I have light periods but August was the worst I was having a lot of gushing and large clots I went through several heavy cloth pads and this mth I had two heavy days not as heavy as August but still not my normal flow

I think my body is trying to get pregnant if that makes any sense but my body is rejecting and cleaning me out

I start vitamin d by perscription around end of July can this be a side effect?

😩😥😥