Awaiting H1B Receipt After Obtaining a J1 Waiver

I am a foreign medical doctor. I will be done with my residency training in two weeks. I am currently on J1 visa and have applied for a J1 waiver for a job as a hospitalist in Phoenix, Arizona. I have obtained the waiver in mid April. My employer and their lawyer filed for H1b visa on May 15th. I am still waiting for the receipt for H1b. I have contacted my employer and their lawyer and they told me it is too early to try to call USCIS to check the status of my application even though I want to only inquire why I haven't received a receipt for my H1b application; i.e, a case number to be able to track my application. I am now nervous because my current J1 visa expires in June 30th and I have no proof that I have a pending H1b application. I also do not want to be out of status after June 30th. I am worried that my employer and their lawyer have made errors on the application and that is causing the delay in receiving the receipt. Is there anything I can do besides waiting and calling my employer and lawyer every week to check if they received the H1b application receipt ?
Thanks

Try using the USCIS online case status check.

well, to check it online you need a receipt number, and neither my employer nor myself have received a receipt number yet.