I am so sorry that you have lost your baby. I can’t even imagine how that must have been hard for you. What have happened? I mean what was the cause of that unfortunate event?
Did your doctor told you to wait some time before try to conceive again?
My cousin had two miscarriages and the doctor told her to wait at least 6 months before trying again but every woman is different so everything is individual.
Considering your question about oral sex the only way it is preventing you from conceiving is when your husband doesn’t ejaculate inside your vagina. So you can relax regarding this and your husband can continue to enjoy in oral sex.
If you are having problems to conceive by natural way it would be best to visit your doctor and talk to him about other options. Today there are so many ways in which science can help you get pregnant.