im not speaking from experience but i've been told that the female can hold sperm from multiple males and any one of them can reach the egg as long as their viable. ( i think i worded that right )
sometimes it can make it tough to figure out what you have. for example, if you breed a male pastel and a male hypo to a normal female and end up with two pastel babies and four normal babies; how do you justify calling the normal looking ones possible hets for hypo even though they just might be?
John