Pregnancy test!

So has anyone ever been around 3 weeks and got a positive pregnancy test? I had a faint positive line but I would have only been around 3 weeks. 2-3 days later I only bled for like 3days my period normally is 6-7 days long and can be heavy but this was a light bleeding. Unfortunately I don't have a vehicle to go buy another test and my husband is away for work so I haven't been able to go put money in the bank or even go buy another test yet. I'm just curious as to is it possible that it could have been a positive that early on or would it just been a evap line?