Need help asap, had a routine gnae app yesterday about period like cramps they done an internal scan and the doc assured me I was pregnant , the did a blood test and came back negative , they said it could be a fluid filled sac nowy head is every where, there taking me down next week for scan and more blood work what does this mean am I pregnant or did they make a big mistake somebody please help

Sometimes the tests, blood or urine, don't come back positive until much later. Unfortunately you'll need to wait the results of the coming test. We can't really say anything more then you have already.