Im bleeding in my first trimester

Anyone here bleed through the whole of their pregnancy?? Im 8 +3 and since i found out (about 3/4 weeks pregnant) ive been on off bleeding red blood when i wipe. I went to ER about 3/4 weeks ago when it first happened.. and 2 weeks ago they called me back for a scan and said baby messuring less than 6 weeks when i was meant to be about 6 +5. Im just really worried. I never bleed once with my son. I also got pregnant on the first cycle i had in over 2 years (since having my son) so im hoping its just extra blood from not having my period for over 2 years.. ugh its scary