Thank you for your query.
I can understand your concern. The swelling behind your ears can either be the normal mastoid bone or lymph
nodes which can only be confirmed following a clinical examination. The mastoid bone may not be very evident in every individual.
The swelling mentioned on the centre of the chest appears to be the xiphisternum which is a normal part of the sternum.
I hope I have answered your query to your satisfaction.
Wishing you all the best.
Rajiv K Khandelwal