I second this and would ad this, I have seen people maiking this kind of statement before and wandered why if you which is the only true judge if you are on the brink if not actually injuring yourself just simply work within parameters that do not cause this example years ago when I was working at a raquet club a member comes up to me and says "Every time I go up to 100 + lbs on the adduction machine I feel like I'm herniating myself, what do you think?"
Seriously? Does this really require someone else's opinion?
I suppose it's possible you just aren't describing a deep stretch adequately but you did say you felt like you were going to or were tearing something, if that is a accurate statement it would not go any further than that in my book STOP!!! Back off the weight tighten up the form but whatever you are doing that is feeling like tearing is not good.