could i be preggers?

about mid-jan 2012 my fiance began asking me about having my period and that he noticed changes and wondered if i was prego; my cycle showed up on time for jan and feb 2012 but was shorter and lighter than normal. in mid feb i began noticing changes in my sleep patterns (cudnt seem to sleep enuff), nausea, certain smells bother me, i became very emotional and starting in March i noticed the cravings for pizza and potatoes all the time; my March cycle was 1 week late so i took a hpt and it came bak with a light positive, 3 days later it came but wasnt normal (im normally a heavy 5 day) this one was 3 days and light enuff to wear 1 pad all day. i have continued having pregnancy symptoms and my boobs have began feeling heavier and i just dont feel right. cud i be pregnant?