I’ve been practising yoga at home for a month and three days. All was well during the initial two weeks, I was enjoying the endorphin rush and the inner peace that yoga gave me. Only for the past week I’ve noticed negative thoughts crop up during my yoga practice and after it, sometimes days after it. Depressing thoughts from the past are reoccurring and are now much more ‘raw’.
Understandably, I’m apprehensive to continue with yoga.
Your advice would be greatly appreciated 
Yoga cleanses body and mind so thoughts will come to surface and then they are hopefully gone but that depends on you. Its not that yoga will give you bad thoughts more accurate is it cleanses you and the side effect is what you experience. Just be strong and dont let this experience stop you. Good luck.
Perhaps realize the past is dead and gone, the illusionary future is simply a projection of the past, similarly time and space are relative because they?re also dependent on memory, furthermore there are no good or bad thoughts they?re simply likes/dislikes of the mind, experiment various ways of staying in the freshness of the never ending real moment not by suppressing memory but understanding and experiencing it for what it is not what you want it to be, just be.
Thankyou
We, as human beings, have latent feelings and emotions. Our appearance and behavior in the outer world (that world which is not within us) is masked so that we “fit in”, are liked, seem normal, and pretend so that the ego is placated.
Yoga is a process which reveals the inner self so that we may live that more fully in the world - as opposed to levitating above the planet looking down upon its woes. When we, through that process of Yoga, meet ourselves it is very common to see some things in our selves that have been buried (latent) or hidden. And now they and you are ready for them to come forth, be addressed, learn, grow, and move along life’s path.
It is nothing to be apprehensive about. Just something to note and not get too entangled with, one way or another. A set of feelings and thoughts, part of you (part of us all) but not something that makes one odd or “bad”.
The energy simply needs to be redirected and that is where the sound guidance of a well trained teacher comes in. Please do consult with he or she as you progress beyond the first month of your practice.
gordon