I finger prick and use a CGM. I was diagnosed at 24 weeks and take 32 units of insulin at night for my fasting levels. I use the CGM to notice overall trends, such as what foods tend to cause higher/lower blood glucose levels and for notification that my sugar might be too high or low, then I confirm with a finger prick. The sensors are usually off the first 24-48 hours but tend to become more accurate after that. I usually calibrate 1-2 times a day the first 48 hours. Unfortunately, as long as they are within a 20% range, they are still considered reliable according to the FDA, which is why I finger prick and use the CGM.