For example, pisces birthdays are from Febuary 19th-March 20th. Would the sun be near or at the pisces constellation during Mid febuary to mid march? Basically, I was wondering whether the astrology we use now is related to the sun's position relative to the zodaic constellations.
Yes, but no.
The basic idea behind the zodiac is as you stated what constellation the Sun is located in during the year. But the time assigned to each constellation (1/12 of the year) is not accurate, for several reasons. Firstly, because of modern constellation borders, some constellations are larger than others. This has also caused the ecliptic to pass through Ophiuchus, not in the zodiac. Secondly, axial precession has rotated the zodiac by almost an entire constellation over the last 2000 years. That is not accounted for in astrological dates.