I have a red mole on my scalp and I'm worried its melanoma. (photos)

See your derm surgeon for evaluation but just from the photos I would guess that it is a benign cherry angioma which is easily zapped and gotten rid of.

That's a great question! 
Just because the mole is enlarging and red does not necessarily mean it is harmful, or melanoma. There are many common, benign growths that this lesion could be. Pain could be from trauma to the lesion (ie: brushing over the lesion). The signs to look for in regards to melanoma are: Symmetry of lesion, irregular borders, color changes of lesion, and size. 
Regardless, if you are concerned with the mole it wouldn't hurt to have it checked. To have a mole removed is a quick and easy procedure! 
You should consult your local dermatologist for further evaluation/treatment. Hope this helped!