Oo, possible talaga kahit 28 days pa lang postpartum, lalo na kung hindi ka nagbreastfeed kaya walang natural protection! A few of us mums learned this the hard way, some got pregnant agad after a few weeks because we thought we were safe, pero ang totoo, you can ovulate bago pa bumalik ang period mo. Definitely check with your OB ASAP para malaman kung pregnant ka na or para mag-start ng proper contraception next time, kasi super challenging talaga ang back-to-back pregnancies sa katawan, especially after just giving birth.