Help please

Me and my bf has sex and he used the pull out method which has worked in the past but when he pulled out some cum got on my thigh and now I’m suppose to start my period tomorrow and I’m not having discharge like I️ usually do but I️ did have spotting a couple of days ago which is weird. I’m not having my usual period symptoms except for my boobs being sore. Also can a infection cause the brown discharge? because I️ had one and now I’m really freaking out because I’m hoping I’m not pregnant.