Where did my period go?

The last time I had intercourse was Jan 6. It was protected but the condom broke. I took the generic version morning after pill Next Choice and spotted for 4 days on Jan 15-18. My period was suppose to start Jan 22 but it never arrived. I took many pregnancy urine test and blood test and they where negative. Did any of u have irregular periods after morning after pill? && If if I do not receive my period this month should I see my doctor or wait it out again?