Late Period, Negative test, could I still be pregnant?

Patient: I am 6 days late for my period (day 38 of a usual 32 day cycle) – I have taken a pregnancy test, which was negative. My doctor said they do not do “confirmations.” I am not stressed, have not gained or lost weight, have not altered my daily routine in any way. Is there any way I could still be pregnant even with a negative test? If yes, what should I do next. If not, what other things could be contributing to a late/missed period besides what I mentioned are probably not the case above?

Symptoms: Late period, sore nipples, increased urination, fatigue