Late period, negative tests!


I have always had regular periods! I EBF and my period returned in December (my daughter was 8 months old). It was super heavy and lasted 5 days. It came exactly when it was supposed to in January and lated 3 days! This month... nothing! I’m over a week late! I did have cramps and aching at the time I was supposed to start but never did! I took a home pregnancy test-negative! I went to the doctor to get flu tested (positive 😫) and also did a urine test-negative again! Is it possible that it’s because I am breastfeeding that it skipped? Should I contact my OB? TIA😊