Stretching with aching muscles

Dear redditors,

my goal is to achieve a good balance between strength, control and flexibility. Last year I started working on my strength, recently I started improving my control by working on my handstand. Now I want to process flexibility into my schedule. After power training my muscles ache relatively long. When I started out they hurt for a whole week, but at the moment it only is 2-3 days. As a result I have nearly constantly aching muscles.

My question is whether it is possible to stretch with aching muscles. The muscle ache from power training is a result of small damages to the muscles. I was wondering whether stretching could aggravate sore muscles or damage them further.

Does anyone have experience with or knowledge about this? If you have them, any scientific sources are much appreciated!