What Causes Diarrhea, Nausea, Hot Flashes After Having Unprotected Sex?

hi there.
I am worried I am pregnant could you help me....
I was on yasminelle birth control pills, did not miss any pills in the cycle but had unprotected sex 2 days after my last withdrawal bleed. Approaching this bleed i had become very pale and anaemic looking, 2 days before due bleed had hotflushes diarrhoea and nausea ,..implantation? have been feeling very strange...spidery veins..looked like blood in urine..every pregnancy symptom in the book.....
then i got my bleed as normal but am not relieved as i know it could be just early pregnancy bleediing.... it is heavy enough flow not just spotting and has been for 3 days.....
do you think i am pregnant or could my hormones just be messed up this month? i have been on birth control 6 months and never had these symptoms so hence i am worried....i know the only way to know is a test but given my story what do you think? I had been stressed with exams during the period before this cycle and have had work placement stress this cycle but i still feel it could be pregnancy,...please advise on what you think....
Thank you.