Generally things like microcosmic orbit training are not that big a deal by comparison to other forms of Qigong training. However you have to be very careful what you are noticing and what you concentrate on. If you are not careful you can cause yourself physical issues and possibly, if you go too far psychological issues as well.
But best advice for all forms of Qigong training was already given to you by Audi
Audi wrote:but have also been warned against attempting it without proper instruction. The main thing I have been warned against, however, is the possibility of causing psychological problems, rather than what you seem to be describing.
basically find a good teacher