To check if your cup has opened fully after insertion, give it a light tug. If it is fully opened and has formed a seal with the vaginal walls, it should not budge. If the cup slides out easily, the cup has not fully opened.Some tips to make the cup open fully:Hold on to the base of the cup and rotate itHold on to the base of the cup, pull it out slightly and let it pop open, then push it back inInsert a finger along the side of the cup and find the part that is still folded, and push the fold out Remove the cup and try another fold for insertion