What kind lf std's would cause watery semen frequent pee'ing both with occasional discoloration. and slight pressure in the pelvic are on occasion?

Non specific: Your symptoms are vague...There are several stds which can produce those symptoms. Best to be checked appropriately and treated correctly- see a physician.

A few choices...: ...Mostly bacterial (like gonorrhea / chlamydia--particularly if not using condoms), and requiring antibiotics after history/exam/diagnostic testing to confirm issue. The pelvic issue can be from involvement of the urinary bladder. See a dr / urgent care / "std clinic" for testing and treatment.