My last regular period was 11th May and lasted 3/4

Patient: My last regular period was 11th May and lasted 3/4 days. I was sexually active between 17th – 27th with use of a condom. However, after he ejaculated, he stayed inside me for sometime before withdrawing. I started bleeding on 28th which lasted just over 24hrs. Since the bleeding has stopped, i’ve noticed my urine is a little darker and i have mild period pains in my lower abdomen. I haven’t been particularly stressed or had any major diet/excercise changes. Its too early for a pregnancy test. I’ve been trying to research what the cause could be, but im met with much confusion – any ideas?

Symptoms: 2 week early period

Doctor: