I Turned 40 Last Week. Had Sex 6/7th July, Unprotected

I turned 40 last week. Had sex 6/7th July, unprotected and I took postinor. Afterwards, I still had menses at the normal time 20-22 July but flowed for three days instead of normal four/five. Had unprotected sex on the last day of my menses 22nd July. Now, on the day, ovulation is expected (30-31 July/Aug 1), my breasts are tender and swollen, I have dizzy spells and i feel bloated in my stomach. And these symptoms have been on for six days. My next menses should be 12th Aug. Could i be pregnant already with these signs?