Those aren't mine, they are just pictures I found on-line to illustrate what I was saying. I put the picture credits for where I got them under the pictures.
So it can't possibly fruit before it blossoms and has both male and female flowers. (They are separate; the female flower is easily identifiable, since it comes with a little embryo melon already present behind it.)
If you have had it in the ground for two months and the vine is only 5 feet long, it isn't getting something it needs. It is too little to be blooming or fruiting yet, but it should be bigger by now. If it is not a dwarf variety, the vine may get 20' long or more.
So you said plenty of sunshine - if your peppers are producing fruit and the melon is getting the same amount of sunshine, I will trust that. Other variables would be soil fertility - melons are very heavy feeders and need to be fertilized regularly- and water. Watermelons while they are growing, blooming, and setting fruit need the equivalent of two inches of rain a week, which is a lot of water -- one inch of rainfall equals 4.7 gallons of water per square yard . Once it has fruit set, you can cut that down.
Also where are you and what has your weather been like? Watermelons need warm soil and three months of reliably warm (80 deg F) sunny weather.
It's why I don't grow them, they are very demanding-- tons of space, sunshine, regular watering and fertilizing to get one or two watermelons.