If the bedikah tomorrow does not turn out to be acceptable, unfortunately you have to do a new hefsek taharah and restart your clean days. If the bedikah is a questionable color, such as brown, you should bring it to a halachic authority for evaluation, explaining your difficulties with staining.

If your most recent bedikah was on Tuesday, and you are clearly still spotting on Sunday, you can choose to skip the bedikah on Sunday and do one on Monday instead, going to mikveh Monday night. But you cannot go more than five days without a bedikah, so you cannot postpone it further. In that case, if you forget to do a bedikah on Monday, or if it does not turn out to be acceptable, you need to do a new hefsek taharah and restart you clean days.

If you are intent on continuing with the minipill, you can just try to be patient, and give yourself some more time to see whether this staining persists. It is possible that due to a change in breastfeeding your hormones were temporarily causing staining and other side effects. However, it is possible that at this point the minipill is no longer a good option for you. You can speak to your doctor about other options including the combined pill, the IUD, or a diaphragm.

Please feel free to get back to us with any further questions.