I am 5 weeks pp, caved & had sex 4 weeks pp with no bleeding, used a condom & plan b just because i do not want to get pregnant again. just started heavily bleeding yesterday is this because of the pill & just having a baby? getting worried?

Lots of hormones: Plan B has large amounts of hormones and is very disruptive to your body. It can cause bleeding to be delayed, more heavy or longer lasting. It can also cause breast tenderness, nausea, fatigue and headaches. It should only be used in an emergency, not as a regular contraceptive. If you are breastfeeding, use a progesterone only oral contraceptive pill for regular contraception.