Maternity Leggings

What are the best, won’t break the bank, leggings you’ve found for working out in? I’ve checked amazon and they have a bunch of stuff but most of it seems like fashion leggings versus actual workout gear. My first pregnancy I did a lot of swimming so I only need a swim suit and leggings weren’t something I needed for that. I just sized up in regular clothes/swimwear. However, I know I’m going to start showing a lot faster this time and I no longer have access to an indoor pool. I’d like to be able to starting purchasing some maternity athletic wear ahead of time. Thanks in advance!