9 days late, 17 Dpo

Earlier this week I went to the DR for antibiotics, being I was 4 days late at the time she did a urine test. BFN. I'm on day 43 of my cycle. Which is the longest I've ever gone. Back in feb I went 43 days as well. My cycles are usually 33 days. Mild cramps, swollen tender breasts. Should I retest?