Should I try fertility supplement?

We've been TTC for a year and a half now. I talked to my OB-Gyn but he brushed the subject aside. I get a heavy period either 4-5 days early or 4-5 days late (sometimes sooner or sometimes later) but only every other month. It's on a regular 28 days cycle every other month so I don't know if I should consider my periods as irregular. An ultrasound shows that I have normal ovaries and no cysts or fibroids. I was wondering if I should try Vitex or Fertilaid first along with a basal thermometer before putting my hand deep in my pocket for further fertility tests. We already have a 2 year DS