Good luck with the next trim. But GO SLOWLY! The beard is looking great. I agree with your growing it longer leading up to the wedding (Congrats, by the way; my anniversary is May 29), and I also agree that the neckline may be just a tad low for your overall length at the moment. A lot of men tend to grow the biggest, lowest, widest outline they can when they commit to beardedness, but those beards almost always get too bottom-heavy, because that's typically where the quickest, thickest growth occurs. As Mutt says, as the overall fullness increases, you can let the neckline creep down accordingly. That keeps the growth in proportion.

And listen to what Randy says about growing between now and the wedding. Getting a fuller beard along the way will mean that she will be getting used to it, and a trim by then will seem like a major concession for any family members who may ask for it, but will still allow you to have a great beard on your wedding day.