Question about total water used?

So, I brewed a Rogue Hazelnut Brown Nectar Clone today, but during the boil I was sanitizing my fermentation bucket I realized that I had lost the little plug that goes into the top of the bucket. So instead, I decided to use my glass carboy. Now, here is the problem. I think I miscalculated and I did not add enough water into the carboy with the wort. Unfortunately, I have not marked my carboy since I have never used it as a primary . So I am not completely sure how full it is or if it is at the 5 gallon mark. I boiled 3 gallons of water. But after comparing the amount in this one to my last brew(I had a picture) there is not the same amount of liquid. I am running out of time today and need to take a gravity reading then add my yeast. Is the smaller amount of water going to bring up any issues? I think I may have lost more during the boil than expected?

Not a huge deal, really. Using the wrong amounts of top-up water will just make your beer proportionately stronger or weaker. Over the years, I've had beers that missed their target gravities by 10 points or more, and it's still good beer. Basically, you just brewed something a bit different but not necessarily worse than what you intended to brew.