Nope. Never have. I didn't think I needed one unless lifting crazy weight. I only had 50 lbs on the barbell at the time. Hadn't even started my reps. I was only setting it on the floor to get into position.
Do you sit a lot for work?
Yep, all day usually.
That can cause an anterior/posterior pelvic tilt. It can mess up your deadlift and squat form even if you think you are doing it right. Look it up, plenty of videos and articles on it online, it's easy to fix.