Go through your results for flights to New Haven in USA with Netflights. Although British Airways usually has the best prices, it's best to double check what's available for your travel dates.
If you don’t have set dates for when you want to fly to New Haven, try searching by month – that way, you can compare airfares throughout the year.
So, if the flights to New Haven don't work for you, you could always try searching for flights to other airports in USA.
Looking at a few different departure airports will give you even more choice. See what you can find. And remember, it's best to book your flights in advance wherever possible.