I have hypothyroidism, pcos, & diabetes. I have lost 25lbs, but am still 50lbs overweight. In March, my metformin was increased to 2000mg daily. My sugars are controlled. I have been trying to concieve for 12 months. I seem to ovulate regularly but my cycle ranges from 28-32, so I'm not sure when I ovulate exactly. At 3-5 dpo, I had Brown spotting after sex, just once when I wiped, what can cause this?