You can indeed have a concurring diagnoses of both, or also very common, to have some but not enough traits to qualify for concurring diagnoses but still have enough to show signs. For example many people also have some form of OCD to some degree even if not enough to qualify for such a diagnosis.

My understanding as limited as it is that self harm can also be present with BP and does not have to be present for BPD. So that by itself is not enough to say one way or another. Some do some don't that's all.

So relax, just because you have some of the common traits of BPD does not mean you are.