Radio silence after offer

[Ashley Renders]

Hi everyone, 

I'm very new to real estate investing -- I've only made four offers and two were accepted quickly, another was rejected quickly for a better offer. 

But, I made an offer on a fourth house on Sunday and I haven't heard anything from seller in 3 days. Obviously my original offer was rejected because the deadline has passed and the offer is void. But they haven't made a counter offer and I'm not sure what my next move should be. 

My real estate agent says she is in communication with the selling agent and she will let me now if there are any other viewings or offers. But I'm nervous about losing this place if a better offer sneaks in. The house has been on the market since October so my agent is encouraging me to sit tight and wait to hear back. Is that the right thing to do? Should I make another offer to avoid someone else sneaking in?  Or calm down and wait for them to respond with a counter-offer? 

Any advice is appreciated!

Ashley