Been with girlfriend 3 months she has genital herpes type 1, unprotected sex throughout now i have intense stinging when peeing but no blisters for 3 days so far. can it be start of herpes? negative mycoplasma, chlamydia, gonhorrea?

Conceivably yes. As you seem to know, herpes lesions usually would develop within 3 days but not always. Other possible causes include adenovirus, especially if you also have sore throat or conjunctivitis (pink eye). Genital HSV1 is rarely transmitted sexually, especially if no sex when she has an obvious outbreak. One of UK's NHS GUM clinics would be excellent sources of care for this. Good luck.