I had a similar scare with my second pregnancy. I woke up to a gush of red blood around 7–8 weeks and was convinced I was miscarrying. By the time I got to the clinic it had slowed to spotting and the scan showed a little heartbeat wiggling away. Sometimes a small subchorionic bleed or irritated cervix can cause bleeding early on. It usually tapers off over a day or two. Rest up, avoid heavy lifting and intercourse for a bit, and keep an eye on it. If it gets heavier again or is accompanied by cramping, it's always worth getting checked again, but a lot of us have little bleeds and go on to have healthy babies.