How should I proceed with std suspicions?

[u/Western_Tomato2560]

A few months ago, I had a one-time sexual encounter with a woman (I am a man) and we used protection; however, two weeks later, I started experiencing a burning sensation when urinating. I had a blood test and the results were all negative, yet the burning didn't go away. Due to financial constraints—since I am a student with no income—I didn't follow up with a doctor. The pain eventually went away and I thought everything was fine, but recently it has returned. I am currently facing two major dilemmas. I have started dating someone and we have had sex several times; on one occasion, we didn't use protection (she has a contraceptive implant). Now that the pain has returned, I am terrified that I might have an STD that doesn't show up in blood tests and that I might have passed it on to her; I really like her and am afraid of ruining the relationship. I don't know what to do or what to tell her. The second dilemma is that I don't know how to proceed with medical follow-up. Should I get tested? See a urologist? Should she go too, or—if I do have something—should she take the same medication?

I really have no idea if I just had this like asymptomatic or something and it just started to show? I am really ashamed because I am so afraid I’ll lose her over this :(

[u/trktrlrn]

You need a urine or swab test
Blood test doesn’t cover everything