Soap Inside Vagina? does it kill sperm

Hi, I don't know if this has been asked before, but does washing your vagina with soap lather kill sperm? For instance, I usually shower before I have sex. I use a little bit of soap lather and insert a finger and will clean myself. I've always done this. After I shower I feel so clean and I usually have sex after. My husband does cum inside me. We r trying to conceive now, but I'm wondering if the sperm dies due to some ph level imbalance? Or does washing with soap creates a harsh environment? Should I just clean the outside and not the inside? I want to get pregnant and I don't want to add a barrier to that if I can avoid it! Please help!