Kinda confused... wat do u think?

ok since december me and my fiance have bn having w/o protection.... since the month of december my periods have bn shorter (only 4 days instead of 7) but they've bn pretty regular n in march my period was 4 days late... i've taken 4 hpt's n they've all came out negative... i've had some kind of pregnancy symptoms such as nausea ( but i dnt throw up), dizziness, always tired no matter how much sleep i gt @ night, my have went from a D to a DD, n ive bn noticing my stomach is startin to stick out a lil bit. i kno u r probably thinkn the signs r obvious but i jus thought maybe i was jus gaining weight until i realized that im only gaining in my stomach, face, n chest... whn i usually gain weight in my thighs n hips... so could i be pregnant or there is no way because ive bn getn my period regularly