The only way to tell if you are pregnant is with a pregnancy test. It could be that your cycle is a little off due to the missed pills, you could be pregnant or it could be a number of other things causing it. Implantation bleeding is light and usually brown in colour as it is old blood. There are many different causes for irregular bleeding so if you are worried go and see a doctor or take a test in a couple of weeks to rule out pregnancy.
Most women do not experience implantation bleeding at all. Most women will ovulate approximately 2 weeks prior to their period being due. So to me, this sounds more like mid cycle bleeding, but certainly, anything is possible. Best of luck to you.
I got my period,a very heavy one and it was 2 Weeks early. I took a test when I stopped bleeding and I am now pregnant. I would take a test to find out for sure..good luck!