The very first four days you wear Ava, it's common for your chart to look very erratic. This is because it takes a few days for the algorithm to understand the portion of the night when you're in your deepest sleep, and until that process is complete, your data may look erratic.
But after those first four days, the data readings you see on your chart are an accurate reflection of what was happening in your body during the night. If your data is still all over the place after the first four days, another possible explanation is that you haven't ovulated yet.
The normal pattern we expect to see is that RPR (resting pulse rate) starts to increase a few days before ovulation and increases even more after ovulation (though this doesn't happen for everyone), and temperature increases after ovulation. If those increases haven't happened yet, every little up and down on your chart looks much more meaningful than it actually is.
It's also important to note that you shouldn't expect to see any pattern in your HRV (heart rate variability) ratio, as this is simply a reflection of your day to day stress levels.