There is never a requirement to look at toilet paper. Even during the clean days, it is often preferable not to look. A woman monitors her status during the clean days through bedikot and white undergarments, not through toilet paper.
We are not sure that we understood your second question. However, a stain, at any time of the month, does not obligate you to perform a bedikah. Generally, performing bedikot is not recommended aside from the requisite bedikot of the seven clean days and onot perishah.
Not all stains render a woman a niddah. The size, color, and surface on which a stain is found may all be grounds for leniency. Please see our articles on ketamim and feminine hygiene pads for further details.
In the event that a stain found during the seven clean days does invalidate her clean days, a woman does not require a new five-day minimum. She may perform a new hefsek taharah as early as that same day! She then begins a new count of seven clean days from the following day.
We hope this clears up your confusion. Please write back with any further questions.