Implantation bleeding

So I was late a week with absolutely no signs of my period coming at all. I took 2 tests and both with faint positives. Then Tuesday evening I started spotting, no cramping just light spotting when I would wipe. The next day the spotting came a little heavy not like period bleeding which I'm very heavy the first day and a half usually .(  my period only last 3 days) I stopped spotting on Thursday morning. I tell my sister in law what she thinks it can be and she mentioned implantation bleeding. Any suggestions on what I should do? I've never been pregnant so I'm not sure what to do. Any help is great. Thanks in advance