Is the arguing & bickering with your partner normal?

My fiancé and I seem to bump heads more now then ever since I have been pregnant. For the smallest things we are disagreeing and not speaking. Is this ok? I hate it because it keeps my mood sad & makes me cry all the time.He gets in this mood that makes me feel uncomfortable as if I'm the bad person. My mother tells me he's going through emotional distress too. Kind of like pregnancy symptoms but I feel he doesn't take my feelings into consideration. I think he feels in using the pregnancy as a crutch to run to but in all reality I'm not. We all know when your pregnant we are very sensitive to everything. I feel he doesn't understand it. It's his first child but it's my second. I'm afraid that this will make me depressed and ruin our relationship. I don't know what to do.