I found out I was pregnant because I had implantation bleeding. It was brown and light pink. It lasted for about 10 days. During around day 5-6 of spotting I woke up in the morning to bright red spotting. Later on in the day I had some more red blood. I freaked out and called my doctor and she told me it was normal to have spotting and to just keep watching it and see if it gets darker and if I experience painful cramps. I never did keep spotting, just those two incidents. It turned brown and pink again and eventually went away. That was when I was 7-8 weeks pregnant and now I am almost 12 weeks and everything is fine. Good luck to you. I hope everything turns out ok for you too.
i am going thru the same thing right now... i know it's scary and i have misscarried before which makes it even more scary... try to relax until you have your u/s... i am now 7 weeks 5 days i have spotting on and off, first ultrasound with spotting showed a slow heartbeat, went for my follow up u/s yesterday and the heartbeat has picked up ... goodluck i wish you well and hope everything is alright