Need some advice and reassurance!

What is your discharge supposed to look like before your period comes? My discharge is yellow like and thick.. plus there is a smell to it. The last time I had sex was in November.. and I feel terrible about it! I’m only 17😭 However it was safe sex we used a condom. This whole month I have been stressing SO much .. so I don’t know if that’s causing my body to make my period late? My stomach as been hurting but I feel like I’m just thinking too much but I don’t know! Does anyone know where I’m coming from? I need some help, I am scaring myself.😣