OMG I NEED HELP..BROTHERS FRIEND..KINDA RAPE..PREGNANCY):??!?

okay so im 15 years old on the 16th i was home alone and my brothers friend got there, i had bearly gotten out of the shower so i was wearing my PJ's shorts and a spaghetti shirt he knocked on the door and came in he said he needed something from my brothers room so i told him to go ahead and get what he needed to get..i told him to hurry up because my friends wer coming over ( they weren't) i said that because i noticed he was blown (high)!! i went into my room and when i was drying my hair he came in he grabbed my arms really hard and threw me in the bed he took my shirt off and also my shorts..he entered his penis into me for about 30 seconds i was trying to scream and get him off of me but he cover my mouth he didn't *** inside me but im sure he pre cumed..i don't know how but i kinda kicked his stomach and i was able to run..he runed after me he tried to force me again but in that moment my brother got there he started to punch him and kicked him out of the house..i told my brother to not tell my mom because shes really sick..my question is can i be pregnant i mean he didn't go all the way i think and he also didn't *** but they say pre-ejaculation also has sperm in it i had bearly finished my period on the 15th..im so sure i was NOT ovulating but im really scared!!!):