Could My Delayed, Light Period After Missing Contraceptive Pills Be Due To Hormonal Changes?

Hi. I started with contracentives about a week ago, while I was still sexually active with my husband. The mistake I did was not taking the pills on the day that we are active. This happened twice, 3 days apart. Now, my period is 2 days late, strangling started off pinkish, and very low, almost like none. Then i stopped the pill, when I realized that it affecting the period. And then the flow got improved. Still not as normal like I am used to but something is happening. Could it be that its just hormonal change in the body or should o start buying pregnancy tests?