I think you're referring to perineal massage. Yung vaginal tissues yung minamassage mo ng pa-U with coconut oil or non chemical lubricant with konting pressure, pero it should not hurt. This starts from 34 weeks, so your muscles can relax and accommodate delivery. Though hindi pa talaga sya proven to be effective, pero you can try or ask your partner to do it for you.
Then you can search for prenatal yoga on youtube din.
Lucky Brianna