Question:
If my wife had seven days without her period, and she went to the mikva without checking with a white cloth, because she has a very rare period due to medication she takes, and didn’t think it would be necessary to do the checks, is she required to begin another seven days of checking?
Answer:
Every woman must make a "hefsek tahara" in order to become permitted to her husband. If she didn't make any bedikos she has to go through the process now. Meaning, she should make a hefsek tahara, count seven days and make bedikos, and then go to the mikvah again.
Sources:
Y:D 196-1, Sidrei Tahara 196-23, Shut R' Akiva Eiger 60.
