Mine left like my stomach muscles were tightening. Like my actual bump was crushing itself. Never felt like period cramps or anything but I did feel pressure. It started off really mild (mild enough for me to drive myself to the hospital) and got really intense.
U will know they are almost uncontrollable some compare to period cramps mine were never ever like that I had shakes so bad and pressure u will just know trust me. I would walk really fast to bring on more pain if it's a real contraction it should get worst and your body is starting to labor if it eases it's just a cramp