Is it possible to be pregnant?

Almost a month ago, I slept over at my boyfriends house. I was naked in his bed and we were messing around. I was still a virgin and wasn't ready to have sex so we didn't. But we both naked and he had his dick around me. He never came at all that night but he did pop my cherry while fingering me. Ever since that night I'm always constipated and I woke up this morning and I'm so dizzy. My stomach is bloated and I keep having cramps but my period isn't coming for two weeks. I had my period after this night 5 days later and I never had sex so I'm okay right? Because ever since this night my body has been acting very different. My boobs have gotten bigger and my discharge has changed and everything! What is wrong ?