Am I pregnant?

Okay so, usually my cycle is in between 27-28days. Past few months it’s been weird. 3 months ago it was 30 days, 2 months ago it was 25 and its last month was 25 as well. I might be over thinking it but today is Day 26 and nothing. I have some cramping it’s persistent for the most part, kinda grumpy a little bit and have no cervical mucus. Also my breasts aren’t sore, heavy feeling or anything. They look normal. I took a test today but it was one of those $1 test from dollar tree and it was negative. Could o be pregnant or am I over thinking?