There are a few things I can think of: If you've lost a lot of body fat, and are very lean, there is sometimes more blood after an injection. Also, if you're hitting veins, which is common when pinning delts, and certain other places, that would be a cause. As far as if you're losing gear, YES!!!!! It's happened to the best of us. The oil will dribble out fast, so you should always be prepared to hold a cotton ball or other clean pad with pressure for a few mins when this happens. To reduce the chance of that, use a longer needle and split your dose into 2 injections if you're injecting 2 or more cc's, IMHO.
The only other thing, which I hate to mention, but is fact... If you have developed any kind of medical issues such as diabetes, super-high blood pressure, or other conditions which cause trouble with blood clotting ability, these would cause the bleeding pin sites too. Please get your glucose tested and use good common sense, if you think you should see a doctor.
Charles