Trying not to worry!

Just been to the Drs who seem puzzled by the fact that I had a 5 day light bleed and then got my BFP the day after, they didn't get a positive there today but she said it's probably because my sample wasn't a morning one and looked very diluted. I have to take a morning sample in tomorrow but because I am still spotting just worried that my little bean won't stick, they wont do a scan until at least 6 weeks and at the moment I am estimated at 5 weeks. has anyone had a similar experience to mine? Did it all work out ok?