I’m a little worried, so advice is appreciated

I had sex June 10th and we wore a condom and pulled out but the condom malfunctioned and we didn’t know if anything got in me so I took plan B. Five days later (June 15th) when my ovulation/fertile window was supposed to start I started bleeding for about 4 1/2 days and it was moderate to slightly heavy bleeding enough to fill a pad. I logged it as a period, was it a period? Also I’m a couple days late on my period but I’m having light symptoms, should I be worried?