Most of them did become pregnant, although they often would practice different kinds of sex, like oral and anal sex. Abortions were a common solution too as were some medical remedies.

Most of these women who got pregnant would give up their babies for adoption or even just abandon them. Some would keep their children and especially daughters, as young girls could also work in the sex industry.

Furthermore, many of these women would not grow old, as their lifestyle, common violence and possible addictions would greatly reduce their lifespan.

hey had choices:
Condoms have been around for a very long time, so they may have had themSome probably were infertile & were probably divorcedSome unusual practices actually worked - peach pit in the vagina, rag soaked in vinegar, douche right after the deed was doneSome probably got pregnant & the baby was given to a couple that had no children or just wanted more (Doc would have connections)Some probably had the baby & kept itSome probably took herbal remedies that could come close to killing the mother but would make them miscarryWhy didn't saloon women in the Old West get pregnant? - Quora