bleeding very heavy

day 16 of me having a period or just bleeding i don't know what is going on it is so bad but nothing when i  am sleeping strange. but if i am standing or sitting down i am bleeding a lot with clots. i am scared to do the pregnancy test that the sonograph ask me to do yesterday. i'd hate to find that i am not pregnant. i will not go to work tomorrow n try n to go to the doctors see what they say. somewhere in me tell me that i am pregnant although i have been bleeding for 16days now.