help i think i am pregnant!! ?

i lost a son just about 5 months ago, due to him preterm birth! at 23 weeks, and well i am scared out of my mind!! test say negative but i kanid fell that i am > cuz i am 6 days late and have had this funny felling in my belly for like 3 days now and i have been supper sleepy and have a sit headache and my hair and face r very greasy! and smelly stuff makes me sick so i think i am and it is just to early to tell by a pee test! what do u think ,? and can i get pg 2 days after my last period? thank you vary much! any advice will be thankful and have a good day!