It could be. I hate to say this because it annoyed me last time when I was waiting to go into labor. You will KNOW. There will be no doubt.
^^This. Potentially the single, least helpful thing, but very true. I didn't feel contractions my entire pregnancy, then the night I went into labor, I laid down because I felt off and suddenly my entire belly went tight (like I'd clenched it, except, I hadn't and couldn't stop it) and my first thought was "that was a contraction".
However, as pp said, it can be different for many people, so it is possible you're having some strange labor pains/pre-labor pains. I think I've even read that sometimes only parts of the uterus contract when it's Braxton Hicks (don't quote me on it!).