Didn't save email with order number?

I ordered a shirt from http://www.merchconnectioninc.com/ for a christmas present and I received an email with my order number. I accidently deleted it, but then I went to my trash bin and "starred" it but I checked back recently and it's completely gone.

Anyway, they said they'd email me with tracking information once it's shipped in 1-3 days. It's been 5 days and I haven't gotten a tracking email. I'm worried if this goes on longer that I'll have to call them to tell them about it, but I don't have the order number. However, I paid through paypal, could I use the invoice ID?

Anyway, any help is appreciated, I'm probably just over-thinking.