re 17 years old Mother.
Mard anzal karsakta hai ... Anzal means Vagina se bahir discharge hona..
Sahaba e Ikram (Raziallah ho Unho) use to do this and our Prophit
Hazrat Muhammad (Sallalah ho Alehe Wasallam) did not stop this aur Farmaya mafhoom hai ke Agar allah ke marzi hoi to aulad ho ge warn naheen
a women can pregnant in this situation.. But why dont you beleive on allah and try your best not discharge inside of vagina...
Family planning is not a good option. She might get problems later when you decide to have baby...