Birth Control Failure

Theresa
Ok so my fiancé and I have 2 kids, have been together 4 years.. You get the drill. Well when we first met I was on bc, we used condoms and then we stopped because we wanted a baby, I got pregnant and had our daughter, afterwards I was put on Mircette, the pill and it made me a moody miserable bitch, I had the worst up and downs, I felt bipolar. So I got off that then got pregnant with our son, SUPRISE! Right after I had him, literally I hadn't even gotten up yet from delivering him and they shoved the Mirena ring up there. When I went back to my doctor 6 weeks later she said its all good and is still in place, this was in April of this year. So of course we were having sex. And in late November we found out I was pregnant again... The doctor came to tell me that "oh it must've just fallen out" ... 🙄🙄🙄 so, basically my question is can anyone recommend a form of birth control to me that has worked well for them with little side effects. I know everyone's different but it's a nice starting point. Thanks!!