Does a D&C or a (burning of the uterus) hurt im so scared?

i had a miscarriage at 3 weeks last year and my old gyno never gave me a dnc because they said i never needed one since my hcg Level dropped below 100. but ever since ive been having really messed up periods. like i wont have one for like 2 3 months or when i do get it ill have it fr about 6 weeks even longer and ive already been to my new gyno about this and they said with a higher dosage of birth control it should straiten itself out.. well its almost 6 months later and still nothing ive been on this period for a lil over a month now. but it's weird though its not heavy at all itspretty lightht. but i may want to ask for to get a d&c or a burning of the uterus to burn the access cells off. two questions please be honest because never had surgery before and scared to have one. so does it hurt when you get done? and two i have a son already but me and my husband are trying to have a little girl, so would it make me less fertile? also would i be able to tell my gyno to test for more reasons why its being this way the only thing they did was a pap test and athyroidd test and both were fine. i thought they would of tested for more.