Hello everyone! Can someone please explain to me what this is! So this…

Hello everyone! Can someone please explain to me what this is! So this morning I got up, felt fine, but around 10 AM, while I was in the kitchen, I bent over and suddenly felt pain on my left side and it felt like I had wet myself, but it turned out my period started, one day late ?? But it's not heavy, just spotting. My stomach and lower back started hurting. Outside, I even thought it was pouring like from a bucket, but actually no. You only see the blood when you wipe.