As a regular swede and without a phd in linguistics, I'd say: There is no difference. The only way I can think of which would emphasize the ongoing action is using the words "håller på att" before the action. This literally means that you are "holding on to" doing some action. But the significance is that you're in the middle of the action. Eg:
Jag håller på att läsa en tidning = I am holding on to read a newspaper = I am in the middle of reading a newspaper / The reading of the newspaper is ongoing.