What would the next fertility option be?

[Elisabella]

I was pregnant and suffered a miscarriage at 11 weeks January 2015. Got pregnant first try. No issues. Had a D&C. Waited eight weeks. Have not had protected sex since then. Doctor did an endometrial biopsy in March 2016. Came back normal. Said I ovulated late. Prescribed Clomid 50 mg. Ovulated CD 17 the first cycle and cycle day 15 the second. Did not become pregnant either time. Had an ultrasound before the third. No cysts. All normal. Was prescribed Clomid 100mg. Ovulated CD 17. Used PreSeed. Did not get pregnant. This is my fourth round of Clomid, my second at 100mg. What would the next options be? Doc would not do the HSG because he said I had no trouble getting pregnant. Could scar tissue from the D&C be causing an issue or am I paranoid? What should my next step be?