Cindy,
I don't think any one else is going to even notice the mistake once the entire quilt top is finished. I think we are our own worst critics. We see all the flaws, because we look at each individual block, as we are making the quilt top, not the entire top. However, if the mistake is something that will bother you, now is the time to fix it, before you get that block sewn into the quilt top. I don't think there is anything worse than having your top all together, and seeing a mistake in the middle of the quilt, and having to rip out an entire row or two, to get to it. But honestly, your mistake isn't something that is going to jump out at any one once the top is complete. Keep up the good work!!!
Diane in Colorado Springs