Do not treat the receipt as an explanation
They may be busy, unsure, forgetful, avoiding conflict, or uninterested. Choose your action from the importance of the message, not from the worst story your mind supplies.
Send one follow-up only when it adds clarity
For plans or deadlines, ask a concrete question and include the decision time. For casual or romantic interest, a light follow-up is enough, then leave the next move with them.
Let repeated silence become information
A pattern of nonresponse may show that the connection cannot meet your communication needs. You can step back without sending a punishment, accusation, or message designed to provoke an answer.