Cramps w\no period

Okay so, I've been having light cramps here and there for the last week or two and didn't think much of it. I was suppose to start on the 17th according to GLOW but I haven't yet. No spotting at all. But over the last two days I've been getting worse and worse cramps. Last night they woke me up multiple times. I've taken gas pills and ibupropfen I'm real tired too. I don't know what it is but it's extremely painful. I've always had extremely painful periods while not on birth control but I just think it's weird that I'm not bleeding. Also last month was a very weird period too. A little late and waaayy lighter than normal with a lot of clear discharge. Any ideas?