Should you?

Should i be able to tell my father that im on my period and bled through my clothes and need to go to the bathroom? my stepmom thinks so. And i think so too except for the fact that well.............i've seen him looking at . And to make things worse my step-mom will say "he sees naked girls all the time in the hospital. He's not a child molestor, but its just that i don't feel comfortable talking about these kinds of things. My stepmom says that to be ashamed to tell him is a "little girl" thing. Im 16. Is this my problem? Should i be able to tell him?