Is this even possible?

I went to the bathroom today(been really constipated) and admittedly I probably strained...but when I got done, I swear my whole left side feels like I pulled a muscle.  It only hurts when I stand.  When I sit or lay, I don't even feel it, but dang it hurts to walk around.,

Okay...so it went away suddenly.  I am guessing maybe its my sciatica acting up.  This pregnancy thing is so weird...

I have definitely had weird situations like that.  Pregnancy is definitely a unique experience.