That's really a personal choice so the only advice I can really give you on that one is to assess how it is making you feel and what would be the better choice for you, you'll feel the same physically regardless of what any one of us else can say. Personally, I've been having a hell of a time with it as well. Bloating like crazy, mood swings, etc except in my case it's the only birth control that I can use. I would definitely get in touch with your doctor as there is a warning that the IUD can move out of place and puncture your uterus without you knowing, and severe pain and bleeding can be signs of an Ectopic Pregnancy. Call your doc and get in asap unless it gets worse in that case I would go to the Clinic. Good luck
P.S. Doctors claim that Mirena does not make you pain weight but its ********! All the people I know who've been on Mirena, and from personal experience have gained 10-30 lbs while using it and claim it is sooo hard to lose weight while on it, while this depends on each person and their body's reaction to the hormones, eating habits etc Mirena has definitely contributed so I feel you on the weight gain!! After this next month i'm probably getting mine out as well!!
it really is up to you if you want to take it out but for me it was an absolutely horrible experince - severe anxiety , heart palpitations, shortness of breath , pain in my legs .................. just awful had copper iud after my 1st child doc raved about mirena -big mistake copper iud gave me no problems except for heavy beeding in the beginning - mirena was removed getting copper iud again