Should I withhold my urine collection if I am menstruating? Nutripath IT Administration September 30, 2022 00:22 Updated Yes as this will contaminate the sample for analyses. Related articles On what day of my menstrual cycle should I collect my saliva, urine, blood or blood spot hormone profile on? Prior to collecting my samples, should I avoid taking my supplementation & medication? How and when should I collect my saliva if I am doing a single tube hormone assessment? Where can I find collection instructions? Is fasting required for my blood test and what should I do to ensure I am prepared for the test? Comments 0 comments Article is closed for comments.