TMI why am I leaking???

I miscarried in March and have had regular periods since then. My last period was 15th of this month, but it wasn't due until the 20th. It lasted my usual 5 days and I'm pretty certain it was a period and NOT implantation. 
Fast forward to today, my breasts feel heavier and more sensitive. SO and I had unprotected sex twice lately--once last week, once threw days ago--and he finished in me both times. 
I highly doubt I'm pregnant. Haven't taken a test yet because I feel as if it's too early to test.  I estimate my next period should be due around July 14-15th. 
I just find it weird that my breasts are leaking. It looks like colostrum to me but I miscarried 3 months ago so I find that odd. 
What do y'all think??