What birth control is best ???

I’ve had a copper iud since I was sixteen and went to the doctors recently for irregular discharge and periods and painful periods to find out my body is rejecting my iud. I need a new form of birth control (even though I am not sexually active or never have been) just Incase the unpredictable happens but any who lol I’m scared to try a hormonal birth control because I don’t wanna gain weight but there’s basically nothing with no hormones I’m just struggling on finding something if someone could tell me what birth control they use and if any side effects have happened to them I’d greatly appreciate it❤️