Missed Period - Not Pregnant

Alycia
Hey ladies! I am pretty sure I experienced a Chemical Pregnancy in September. I was almost two weeks lets for my period in October so I excitedly took a pregnancy test. It was negative. I have taken a few more since and nothing. I am very regular and have never missed a period before (I am 25)  I'm wondering if the chemical pregnancy messed my cycle up? I was using ovulation strips in October and never got a positive. So I'm assuming I didn't ovulate. How long does one wait before consulting a doctor with a missed period? I'm trying not to freak out and just hoping my body gets back on track soon. ?