Are air bubbles that pop when I touch them normal to have on top of my sternum a few days after Breast Augmentation surgery?

This Is perfectly normal and will disappear in the next few weeks. It is from air and fluid (irrigation, local anesthetic, serum, etc) in the pocket which will be naturally absorbed over time.

Thanks for your question. Likely there is just a little air trapped in the pocket. Your body will absorb this. If it becomes more pronounced, you should contact your surgeon. Best of Luck!

Air bubbles are common as the skin probably has not sealed yet, hard to get synmastia under the muscle as there are still lots of attachments along the sternum, may take a few weeks for the skin to settle back down