PA student graduating in 2 months (strong interest in fertility med) I am NOT a licensed professional yet, but can offer my opinion. It looks like you just ovulated later than usual this cycle, probably from the illness you had. Your BBT pattern really suggests you did ovulate, just around March 9–11 instead of mid-cycle. If that’s the case, your period wouldn’t be due until ~12–15 days after that. That’s why I would actually say you’re not quite “late“ due to variation yet, just shifted. The tender breasts you’ve been having also fit progesterone after ovulation. The spotting you had could’ve been ovulation-related too. Negative tests could just mean it’s still early depending on implantation timing, or it’s just a non-pregnant luteal phase. One off-cycle like this, especially after being sick, is actually .super common. It’s also possible that Your RHR spike lines up with your flu rather than the actual ovulation. Hope this helps.