Need advice

Bridget

Today is cycle day 33 of a 28 day cycle and my period is 5 days late today. I took a HPT the day my period was due with FMU and it was negative. I took an HPT at 4 days late in the afternoon and it was negative as well. I’ve been having mild cramping and a lot of back pain that I never get. Could I still be pregnant? When should I see my doctor?