I don’t know a ton about birth control, but I do know there are often strange effects and hormone changes can also influence things. But yes, there is always a chance that you could be pregnant. Though pregnancy tests are accurate a majority of the time, they are not always. I suggest abstaining from sex and finding out for sure if you are pregnant. Go to optionline.org and type in your zip code to find the nearest Pregnancy Help Center. They can give you FREE and CONFIDENTIAL help and advice! They will help you figure out for sure if you are pregnant and are there to support you. Whatever the results, each child is such a gift, and more precious than we know! Let me know what you find out <3 Renee