Well, SciPy depends heavily on NumPy, which as a CPython-specific extension won't run on other Python interpreters in general. Although for example there is ulab for MicroPython which replicates part of NumPy, and PyPy has a compatibility layer for CPython extensions.
Edit: well, Regessio itself also depends on NumPy, but might be able to run on top of ulab whereas I really doubt SciPy would.
Responding that there's something out there called ulab doesn't really answer my question, which was: where does op's requirement to not use scipy come from.
".. I had to generate confidence intervals on over 8000 univariate data sets using very small VMs, so I needed to limit large dependancies as much as I could. This package was the result of this!"
Based on the comments in this thread, it may be worth trying to make this package not dependant on Numpy as well?
Why the requirement that you can't use scipy?
Have you heard of the package stats model?