I have some blue mystic that I am currently smoking that has been curing for about a month. It is sneaky, super smooth smoke, it does not hit you for a few minutes so it is easy to over indulge. 
I started 3 Nirvana Blue Mystics myself at the same time you started these. Mine were above the soil on Feb 1st. Growing in 1 gallon pots withOF soil straight out of the bag. Each of the 3 is very distinct phenotype and now after the fact in doing some research I have seen a couple of posts around saying Nirvana has had problems keeping the BM stable. They all started out the same till about the Day 17 mark at which one plant shot out her first pistols! 1 more a couple of days later and the last one was maybe at Day 22. At this point they started taking different roads. The first flowering plant did a small stretch at topped out at around 15" tall, the second plant has stayed about a foot tall while the third is over 20" tall. I have fought what I believe is a cal/mag problem the whole grow with all 3 plants. Going by the trichromes I took the first plant down on Day 51 yield was 100grams wet. The next plant is no where near ready, she is really packing on the weight and for being the smallest of the 3 plants she is already ahead of the one I already chopped on yield I believe. She looks just like the one in your picture from today. The last plant which is the tallest plant is going to finish very well I believe. But she is so far behind at the same time. She has 12 colas that are going to fill out very nice...but I am just waiting on her to real start filling out. She is also the only one with a lot of purple developing in her buds. I will say the smell from the first plant is crazy good...very heavy berry smell. The other 2 have not really started to smell yet. For what its worth these have been the first time I have worked with auto flowering plants.
Good luck with the rest of your grow.
I've got to grow some! I've put them on the grow list, should have them in dirt by May of 2020................lol!
Keep up the good work! :Sharing One: