HI.. Thanks for asking Health care magic.... I can understand how a 19yr old girl feels with Alopecia universalis.. I know how many hopes you might be having.. Alopecia universalis is immune over reaction.. i mean cops we have in our body to fight diseases are bothering innocent people along with criminals.. So its problem with genes which is not in our hands.. Coming to your blood test.. Actually there is no blood test which can diagnose or rule out alopecia.. So its not possible to say you dont have it.. Coming to solution.. Treatment options are Steroids and immune modifying drugs which needs close monitoring of Physician.. If situation doesnt respond going for a wig is better than to irritate and spoil scalp skin health.. Coming to your current situation and possible progress.. Alopecia is most unpredictable.. Hair can be completely lost.. can grow back partial or complete and can again fall off. so anything is possible literally... So consult a dermatologist.. try the treatment for 6-8 months in which 40% people get better and dont get depressed if it doesnt get better.. and who knows science may find a best drug in near future as research is going on seriously... I have to explain possibilities as its not good to give you false hopes.. Having said all these.. let me remind you Gandhi a famous indian leader in world history doesnt have hair on his head... Mona lisa is most beautiful painting of a lady without eyebrows.. Every human is given unique situations and problems to make them unique.. All the best ...