I had tenderness for a few days before I ovulated until a few days after. I also understand that breast tenderness is a huge symptom of being pg.!
I had no breast tenderness at all with mine, just other symptoms.
I think it is after you ovulated when your progesterone rises.
I have extreme breast tenderness so bad that I had to wear a sports bra to bed on June 30, only 6 days after conception. This is also month 2 for me on provera and clomid . So it can be really early. Today bfp!
Clomid gave me nipple tenderness. It wasn't the whole breast, only the nipples. It was very intense but it doesn't occur until serveral days after ovulation. At first I thought it was hcg trigger shot or pg, but I goodled it and found that many other women have the same side effects.. I also had a cycle were I wasn't on any clomid but still did trigger shot, and I did not have the tender nipples that cycle.
Good luck to you..