You can get pregnant even if you don’t have your period after giving birth.
Postpartum due to breastfeeding will delay the onset of menstruation, usually in 4-6 months will resume menstruation, but before the recovery of menstruation, a woman may still ovulate, and most of the recovery of ovulation occurs before the recovery of menstruation, so there is a certain probability of pregnancy. Everyone has a different recovery of ovarian function, and it is not scientific to blindly rely on breastfeeding contraception.
Without special circumstances, contraception is needed when you start having sex after 42 days postpartum. Breastfeeding has some special characteristics, you need to avoid choosing oral contraceptives containing estrogen, the drug may be secreted through the milk.
Contraceptive options available during breastfeeding include the use of condoms, intrauterine devices, etc. Seek the help of a specialist if necessary.