should i be worried?

so tuesday and wednesday i came home after school and used the bathroom when i wiped i saw blood and brown discharge the bleeding stops about 20 mins after that and is super light but i had my period 8 days ago so i'm kinda nervous i also had sex on monday if that could be the cause of it i'm just really scared something is going on and i hope it doesn't happen today but it doesn't happen at school only at home?