Spotting and it should be AF on Letrozole

So I am usually a 28-29 day cycle on letrozole. I do not ovulate on my own. On CD 31 I started spotting and it’s 3 days later and I’m still just spotting very little there when I wipe nothing on pad. I don’t know if I should count this as CD 3 and take the letrozole or if I should take this month off. Going to call the doc but wanted to see if anyone else experienced this. I took a hpt on CD 31. I have PCOS and do not ovulate on my own. I was having very regular cycles on Letrozole this is the first month anything weird has happen. Any suggestions?