Period

I’m worried - I am supposed to start my period today and have been having symptoms like acne, moodiness etc. However I’ve just gone to the bathroom and had clear stretchy CM. I had sex three times this month using condoms, and I took the morning after pill after one of those times. Is this normal? Like is this because of the plan b pill I took, a normal monthly thing or is it a sign of pregnancy? I really can’t babe a child at the moment.