felt great whole time until last few days, is this it?

PeanutButterGirl

I'm almost 33 weeks and have for the most part felt really good. Had some bad days but never puked and have been exercising and doing yoga whole time. All of a sudden I feel so physically tired and have lower back pain! Today I felt like a truck ran me over. Has this happened to anyone else and will it get better or is this it??? I know everyone is different, but guess I'm just looking to hear others stories.