Respected user, hi I evaluated your query thoroughly.
*First possibility is of heavy 
Urinary tract infection ( you may have UTI even if
  you have antibiotic because there may be infection through such organism
  which are resistant to that particular antibiotic ), secondly Vaginal bleed 
  less  likely.
*Utmost thing you have to do is to relax , calm because 
anxiety will worsen
  your symptoms.
- drink plenty of liquids preferably boiled water, coconut water, rice water, 
  green tea, coffee, home made juices, butter milk .
- for temporary relief from pain can take Tab. 
Acetaminophen single dose
- keep genitals clean, dry .
- consult your ER , get reports of Laboratory , 
Ultrasound abdomen Pelvis 
  done & treatment accordingly.
 Hope this clears your doubts .
 Thanks for using Health Care Magic & giving us a precious opportunity to
   serve you in your really needed 
medical help.
 Wishing you fast and speedy recovery from the same.
 Regards dear take care.