If you have a low platelet count, you may experience: 1  red, purple, or brown bruises, which are called âpurpuraâ. 2  a rash with small red or purple dots called âpetechiaeâ. 3  nosebleeds. bleeding gums.  bleeding from wounds that lasts for a prolonged period or doesnât stop on its 1  own. heavy menstrual bleeding.  bleeding from the rectum.