British Columbia: how do melons pollinate?

i have just planted a watermelon plant, a zucchini, and a pumpkin and 2 squash.

i know that watermelons and pumpkins have both male and female flowers on them and im thinking the rest do as well because there all the same family. now i only have 1 of the watermelon zucchini and pumpkin and was wondering can the male flowers from the plant pollinate the female flower's even though there in the same plant?

 

I don't think there is ever a problem with that as most times insects do the pollination. Doesn't matter whether they're from the same plant, as long as the flowers are being fertilised.