Help!!

So I need some insight so I got my hormonal IUD out taken out yesterday and I had a period June 14 to the 18th and before that I didn’t have a period for like six months and I was told to use condoms until my birth control came in the pharmacy which I did, but I had an incident yesterday where I was worried about semen exposure so I bought a Plan b yesterday and I took it, but today ended up having really heavy bleeding and cramping. Do you think that means the Plan B worked? I’m really worried the period tracker app I’m using only has June’s. Logged but it says I’m supposed to ovulate on the 28th so I’m really worried..