Implantation bleeding?

CA

Hi guys, I’m going to try to make this short. My period is somewhat irregular but I still get it every month. I stopped nursing last month. I had unprotected sex around ovulation and then 4 days later I had some light spotting that lasted maybe a few hours. My period is not due for another 10 days or so and I drank a bit of alcohol the night before the bleeding. Could this be implantation bleeding? If not, what could it be? We’re not trying and not preventing since we needed fertility help with our March baby, not sure how I feel about having a second one but it would obviously be a blessing if I were to be pregnant. Anyway, I’m just confused about the spotting. Any insights? Thanks in advance