As long as your not bleeding so bad you fill a pad or panty liner, then your fine.
That's been happening with me for the last 3 weeks on and off I'm 9 weeks now.
How far along are you? I have found it to be very common to be spotting around 5-9 weeks. As long as you aren't bleeding heavily, you should be fine. Try not to stress, it is just implantation bleeding where the embryo is planting itself.