Help me feel less guilty about leaving work...

I'm about 33 and a half weeks, and today I've decided to leave work for the remainder of my pregnancy. I feel so guilty about it...like I feel like I am letting women down by not pushing through until the end. I feel like people are judging me and thinking I'm using my pregnancy as an excuse to not work. Normally I'm a really hard worker and do my job without complaint, but I work at a Saw Mill, and work physical labour, 12 hours shifts that switch between nights and days with only a day and a half to two days to switch my routine from nights to days. I've found that it has become really hard on me at work. When I'm at work, I get constant Braxton hicks contractions that won't go away unless I lay down but I can't find a time or place to do that at my job. I also get bad headaches and I have been getting alot of pelvic pressure and I can feel my babys head lodged down there which makes being on my feet most the day really hard. But I still feel like those aren't good enough reasons to leave work... But at the same time I just feel like it's pointless to keep putting myself through the stress of going to work when my benefits at work cover me to leave now and still get full pay until the baby is born, and at that point I get one year of maternity leave with 55% of my pay. So financially, I am set and am not worried at all about that aspect... I just feel guilty leaving work at only 33 weeks. I keep hearing about all these women who work until they basically deliver (I have no idea how they do it and I have sooo much respect for them) but I'm just so exhausted. Is it normal to want to leave this early... or am I just being a big suck??