Yes, you may rely on this moch and continue with your clean days.

In general, if one fails to perform a moch, or it gets lost or ruined and cannot be checked, the hefsek taharah remains valid and you can begin counting the clean days.

The exception to this rule is that, if a woman began bleeding for only one day and on that same day performed a hefsek taharah, she must have a valid moch dachuk to begin her clean days. This is usually not relevant due to the five day minimum waiting period prior to the clean days. However it can sometimes occur if a woman experiences a new blood-flow during her clean days and is able to get a clean hefsek taharah that same day. In such a case, the moch dachuk is an absolute requirement.

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