If you check the cloth beforehand and it is clear, and after performing the bedikah you see tiny red spots, unless they are easily removed fibers (perhaps remnants from toilet paper or threads from a towel?), the cloth should be brought to a rabbi for evaluation.

If this is a regular occurrence and your rabbi declares the tiny stains to be kosher, you should ask your rabbi if you have to bring them in every time.

Another possibility is that you are easily irritated by bedikot and the tiny spots are from vaginal irritation. You can try slightly moistening the cloth with water before performing the bedikah, or alternatively, moisten the vaginal area with a water-based lubricant before performing the bedikah. You may also reduce the number of bedikot to see if that helps avoid the tiny red spots. Start with one bedikah per clean day (instead of two), and if the spots still appear, you may reduce to the hefsek taharah, and one bedikah each on days 1, 7, and one of the intermediate clean days.

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

B'Hatzlacha!