I only had my mirena (levonorgestrel) for three weeks can i get it taken out if i'm cramping a lot?

You can: Do anything u want, it's your body. Try to hang with it, maybe even a month of the pill or aleve (naproxen) 2 2x per day. The device is expensive and good contraception. U usually get used to it. If your peeing a lot you could have a UTI which will make u cramp. Remember, the device is about 8$00 dollars as well. Get seen, make sure it's properly placed but try to give more time if u can tolerate.