Wedding guest

I'm supposed to attend the wedding of a good friend in three weeks. I will be 35 weeks at that time, and will be required to travel 4 hours away. If I were not feeling so tired or if I were not pregnant I would attend, no questions asked. But I am exhausted, cramping, and just want to lay on the couch after work. My question is would you attend the wedding? I'm having major guilt and trying to choose between what I should do and what I want to do.