My period is normally regular and has been starting on the 24th since February. Although, last month it started on the 23rd. My boyfriend and I don't have sex. We do, however, "dry hump" quite often. We do this with layers of clothing in between never even just underwear to underwear always shorts, pajamas, etc. he sometimes does pre-ejaculate. He hasn't fingered me but has vigorously rubbed over my panties. Today is the 24th and I didn't start my period nor do I feel how I usually do before I start. I also threw up a clear fluid in the morning about two weeks ago. School has recently just ended and my sleep schedule has changed. Is pregnancy possible or am I paranoid? Please help.