late period, now abnormal bleeding

Yolanda

Hello ladies! So my last period came nearly 4 weeks late. The flow was normal, and it lasted the usual 5-7 days. That same period ended a week ago, and now I'm experiencing stomach cramping and light bleeding. yesterday it was light discharge and now it's a bit more (to when i wipe it covers a square of tissue). my partner are ttc and had unprotected sex last night. what can be the cause of this bleeding?