6 weeks PP sex made me bleed again

Fall • Mama of two 💖💙
So I was good and waited for 6 weeks to try to have sex again. I haven't been cleared by the dr but that's only because they won't see me for my PP checkup until I pay my $1100 left over from delivery. We used lots of lube took our time and was careful but I had some pain and had to tell him to stop and I started bleeding with small clots. It's been about 2 days now it is starting to get lighter but has this happened to any one else ? Also if anyone has suggestions on BC that's cheap to use or get that is safe with breastfeeding please let me know as I can't get another nexplanon for the same reason as above