What's happening

I was home alone and found this brown stuff in my pants at first I thought it was poop, but it kept on happening day after day for about a week I thought it was my period but didn’t know how to tell my mum because it didn’t really look like blood so I used toilet paper. But yesterday it started again and I had swimming today but I didn’t know how to tell my mum so I went swimming today ( luckily it was dry so none came out) but I got home today and it was gooey I don’t know what to do so I’m waiting for the actual red blood to come out so my mum will notice ( she does the washing) or for her to realise because if this isn’t my period how would I tell her.