Yes, unfortunately you can. And this very type of scenario happens all the time. It may seem unfair (and in most cases, it is very unfair), but understanding what can be done about it is very important as well.
When an individual is charged or cited with Assault, he or she is said to have been an unnecessary aggressor towards someone else. In essence, the citation is saying that you should not have made an aggressive move towards the other person (whether the move involved physically touching someone, or simply verbally threatening them with the idea of physical contact), because doing so was not necessary. Of course, if you are defending yourself against someone who is attacking you, this logic seems to fly out the window. But as I mentioned, this is very frequently how these scenarios play out.
Let me give you an example: You are having a family meeting at which your husband’s ex-wife is present. You and she do not get along at all, so you try and stay away from one another. The next thing you know, she (the ex) is coming towards you screaming and flailing her arms in the air. She rushes up to with such force that her body collides with yours, knocking you back a little bit. In defense, you push her back away from you. Once things have calmed down, you leave and go home. Later that night, you receive a phone call from a police officer who begins to ask you questions about what happened. The next day, you are handed a citation that says you are being charged with Assault in the Third Degree.