please answer need advice?

ok had unprotected sex on 21st july and took morning after pill one after. a week later I did an std test which came out negative but I am aware I would need to retest in a week. but on the 3rd I started to get symptoms where I had abit of pain when I sat down and keep going toilet all the time. but no pain passing just frequent. went doctors he dipped my urine and said I have an infection so gave me antibotics which I am supposed to finish on Monday. the pain has gone but I still have the frequent urination. prior to this I did however take a further two morning after pills one was 10th june and the other was 26th june both times with them I bled at my normal expected date for 4 days. I also did pregnancy tests which came out negative. can anyone tell me what may be happening as with the last morning after pill I took on the 21st July I bled for two days a week later and haven't bled since. yet I did a pregnancy test yesterday and it came out negative. my questions is this

is my body so overdosed that probably causing my symptoms?

when can you do a pregnancy test where you get a clear accurate result?