I highly recommend getting a FlipBelt! They’re marketed as an athletic tool to keep you phone, keys, etc in while yo run, but it also happens to be flat & easy to hide under most clothing. I’ve had mine for years now and the only thing that it’s noticeable under is a tight-fitted dress (though to be fair I don’y think any belt would be well disguised under tight material). Super comfortable and stretchy, different sizes, multiple colors to chose from, I hope you consider buying one!
I am loving the workout pants and tops that have pockets I bought at senitaathletics.com. Great quality and very affordable! Highly recommend the pants for pumps.
I have a t:slim pump and I was really worried about where to put it when I first got it. I bought a multiway body band specifically meant for insulin pumps, and I LOVE IT. I wear it with literally any kind of outfit! I’ve been using it for about 2 years now, and I would never go back to using a pump clip or a leg band or anything. Here’s where I bought mine from (it’s a line for diabetics made by a diabetic!) :
For many years I have worn my pump clipped to the front, center of my bra or aerobic top. The front of the pump is against my skin; the pump faces upside down so that the line comes straight down to tuck in. It’s perfect when wearing dresses, even tight ones; pretty much invisible. After 27 yrs T1, this is the best way I’ve found to wear it