I think Braxton hicks? Help?

The past week I've had 2 episodes where I basically get really bad period cramps and everything feels tight down there so I'm assuming what I'm feeling is Braxton hicks but since I'm a first time mommy I really don't know what it is I'm experiencing. My husband and I had sex yesterday and I know those can cause cramps but it's almost been 24 hours and I've had pretty bad period cramps off and on since then. They do go away and I feel better but then they come back and I feel like I need to bend over or something. I've drinken water and taken Tylenol and gone for a walk and nothing makes them go away. Is it normal to have cramping this long after sex? And do you guys think what I'm feeling is just sucky braxton hicks? I don't want to overreact, I'm just such a newbie haha