What do you ladies think?

So this would be the first month that my hubby and I trying to conceive baby#3. It's usually takes me three months to get pregnant once we starting trying. Well anyways, today I noticed I had some mucus(tmi) which I usually don't get before my period. I am suppose to start any where from yesterday to Wednesday ( I'm off on my periods) what do you ladies think, a sign of pregnancy or upcoming period?