Change in AF since TTC?

Why have my periods only changed since TTC?

TW. mentions of MC

I am month 2 of trying (after a MC in October), so cycles were back to normal before we started tracking and trying)

I have a normal standard cycle like clockwork. By in particular this month, I was 5 days early (never happens) medium flow 2 days, nothing 3rd day then today some very light spotting.

But I have had back pain, bad cramps (never really get them), and feeling nauseas on and off.

Testing negative.

This sounds dumb but is the change because maybe my body is getting ‘pregnant’ but then immediately failing? Hence the change in cycle?? I can’t make sense of it and no group I post in can give me a response to help.