Odd Bicep Development

I’ve noticed how my biceps having growing larger at the ends (the elbow side) and not in the middle and not on the end towards my shoulder. Is this possible or am I imaganing it? They’re not huge to begin with, but there has been some noticeable growth over the past 2 months and ive noticed a rise just by the crease of my elbow joint? Is it a specific result of certain bicep exercises I have been doing?

Thanks in advance.