I am looking for indicators that my saddle seat may be too small.  Nothing specific to describe but I have always ridden in a 14" but recently put on about 10 lbs.  

10lbs shouldn't make too much of a difference honestly. But if your legs are filling up the opening, or you find yourself popping out often it may be time to take alook. Sometimes also you may just need to adjust your stirrup length. This spring I was having hell thinking I was falling forward out of my saddle, turns out my growing 4 year old was just hip high and I needed to lengthen my stirrups one hole. Problem solved.

I feel like I am popping out more.  I will try dropping my stirrups.  Thanks!

How tall are you how, how much do you weight? I'm 5'7 and weight anywhere from 154 to 160 and I ride in a 14.5 to a 15" depends on what saddle I'm using. 

Check out this video, it talks about saddle seat size at about 3:10.

https://www.youtube.com/watch?v=DXFabINH1_E&ab_channel=CoatsSaddlery

I am 5' 3 and weigh 148 lbs.  I wear a size 10 jean comfortably if that helps.  I have an older Martin Crown C.

Thanks!  I will watch it.

Dropping my stirrups was the answer!  Thanks!  It felt weird at first then I made a run and wow couldn't believe how much better I sat the turns.