Implant advice,

I'm 17 almost 18 & have been on the implant since 15, so I'm almost at my 3 year mark! the first two years were great, I have been sexually active for a little over two years & recently have been having problems. I am on my period constantly & then randomly it will stop for about 3-4 days about every month or so. & the weird part is when i do finally get off of my period the first day is normal then the second or third day i don't have a lot of discharge but if i try to have sex or put anything up my vagina & pull out theres tons of chunky white dicharge w no smell. then the next day I'll wake up & it does smell for a day or two. then bam i'm on my period again! has anyone else had difficulties w the implant? or am i having another kind of issue? is there a better birth control i should be on that is just as effective? just want some advice! I do have a doc appointment soon though 😊