constant cramps :(

So a couple of months ago I got the normal cramping before my period, and during, and since then it just haven't stopped, I've been constantly aching, I've been to the doctors a couple of times, they've done all sorts of tests which all say I'm fine.. I know I'm not pregnant, I've taken multiple tests.. I'm not on any birth control, and I'm pretty healthy normally? What's going on? And what can I take to ease this? Tired of Feeling like crap!! 😏