Missed periods. Intercourse with my par!

Hello doctor,I am 20 yrs old girl. My situation is too complicated,only you can guide me. In the month of December I had taken medicines to postpone my periods as I wanted to attend a wedding due to which in month of January I had my periods delayed by a time period of 7 days. I also had intercourse with my partner on 2nd and 3rd of January and had taken contraceptive pills .My Jan periods were on 26th of January. I had next intercourse with my partner of 1st February and he ejaculated inside me. On 3rd of February I had a severe urine infection and so I took pills around 66 hrs later the intercourse. After 7-10 days of taking pills I had bleeding along with pain and cramps,the one similar to menstrual bleeding. It lasted for 2 days. As I mentioned I had my last menstruation on 26th january and I am still not having my monthly periods. I checked for the urine pregnancy test on 5th of February (i.e. 7 days after missed periods) but It tested negative. I had next intercourse with my par