Ah ... well hon, if you haven't already have a look through the other BFP's. With most of them on the first test you really do need a bright light and a good eye to see them. Yours is very very easy to see, and pretty much the same width as the control line instead of the very thin lines you see most of the time. So show your OH the other pictures and he'll see it's definatly a very real and strong positive!
Now people do say that you get stronger test results with twins ... *whistles innocently* ... sorry, had to say it! Don't want to get your hopes up though, they're not all that common. Once again, hope you'll have a happy and healthy 9 months =) Don't forget to let us know once you've had your scan done!