Please,please..Girls explain me whats going on with me!!!?

Hi girls...im writing again..may be somebody could explain me whats wrong with me..tell you full my problem.my lat periods was on 14 of december..so after i decided to come off from pill.when my periods stopped after 7 days was bleeding again for 4 days.all that time till 4 of january i had intercoure.,no protection.and every 3 days after..my periods suppose to start on 11..so it still didnt.i did a test (first response) before 3 days my periods suppose to start and after (cheap one)on first missing day.all was negative.and last week i got swab result i had bacterial infection.i didnt have any symptoms,only white thick discharge..but got course of antibiotics..but i still have them discharges.so i know some woman could have them when they are pregnant.before i suppose to have periods i had a period like pain and backache.now i just feel cramping only from right side and in the middle of my belly..sometimes i feel very down of my belly like somebody inside me touching with the needle.what do you think girls am i pregnant???and why i feel this strange crampings?and if im not pregnant why i dont have periods?i dont have pregnancy symptoms apart that i started at a lot and always hungry and my stomach always feels empty.im scared if im not pregnant it could be something serious with me.Thank you very much for any advice..xx