Looking for insight

I'm 27 and have always had moderately heavy periods. I use Super absorbency tampons and change them three to four times a day and usually overnight. That has gone down *slightly* since my son was born end of 2017, but would definitely still consdier my periods to be on the heavier side. Suddenly, as my husband and I decided to TTC last month, I have had cramping, sore breasts, and two very light periods.. I used a hpt the other day before this second light period started and it was negative. Ive made myself a doctors appointment, but has anyone had anything like this happen? What was the result? Thanks