Help! Need advice

Erika
My cycles have never been regular, so always hard to determine if I am "late." Longest was 43 days, which was a couple of months ago and we thought I was pregnant. I'm now at 50 days since the beginning of my last cycle. I have never had one that was this long. Not sure what to do. I have taken one test a week or so ago which was negative. Should I test again?  According to glow I'm 18 dpo and the last time I tested was 10 dpo?