Pregnant or irregular period from pill?

I keep a period tracker and my cycle changes every month from a 25 day cycle to 23 or 26 day cycle and longest 29 day cycle. I had a period January 23, 2018-January 27, 2018. Then I was with my boyfriend and he was trying to have sex but I didn't want to. He initially put a condom on , but I told him no so he took it off. Then he put his arms around me and down in my pants. He stuck his fingers inside my vagina as I was trying to pull them out and then he pulled them out. He touched his penis before he put his fingers inside me. I'm afraid im pregnant from that. Is that true? I took a plan b pill February 5 , 2018. This was less than 24 hours after what happened My period tracker says my period is due February 19, 2018, but I had bleeding already 3 days starting February 12, 2018 and the bleeding stopped February 15th, 2018. Im not sure if that was my period or if I'm pregnant. I took a pregnancy test today and it was negative, but this was the shortest cycle I had (20 days).