been brown spotting for 3 days and nothing when I wipe

I usually get this for a day or so then witch arrives but nothing as yet I did have unprotected sex but didn't finish in me although could sperm leak into me I'm scared it's a new relationship and waited for 5 weeks to do anything he said to me the other day he's ready now to be a dad and he wants a baby next year so I in a way it would be great but also it's quick not even living together yet taking each day as it comes. so I don't know if the brown spotting was my period or not as last month I started the same thing then she arrived.