There is a BC pill that is progesterone only, I don't know brands but I took it while I was breastfeeding because estrogen can affect milk supply. It has a slightly higher failure rate than the estrogen/progesterone pill, but is still highly effective if taken at the same time every day.
Condoms are another option.
the same thing happened 2 me i ended up getting the copper coil in there is 2 types that is the 1 with no estrogen in it gl