What are early pregnencies? Does they cause false negitive results in home pregnancy tests?

i need your help , so my period went off on Saturday. my boyfriend and i had sex both Sunday and Tuesday . both times we had protected sex, but it is now Thursday and i have severe cramps and i am bloated. i know that it is not my period because that just went off. so please, any advice? answers?. i am very concerned and would really like to know. iwanted to know if that means i am pregnant?