I've got blueberry bushes in my garden and as long as they produce flowers, these set into fruit, so as yours has got berries, it must have flowered, so it would be too late to pollinate it. I would just let it grow.
Hi Tiggertan, I bought my first blueberry bush this year. I hope you get a good harvest. Just a little advice that I read on the care leaflet that came with mine. You should keep it well watered, using a high potash liquid fertiliser such as liquid tomato fertiliser once a week, and a rhododendron and azalea liquid fertiliser fortnightly. Good luck