Does Doxycycline 100mg Cause Nausea And Loose Stools?

I'm taking doxycycline 100mg and metronidazole 500mg together for a vaginal bacteria infection, but this is going on my sixth day, I feel weak, i have a nausious feeling, loose stools, dark urine, severely decreased appetite and sometimes get severe jabbing pains in my pelvic area. Im worried I may be reacting or should I just tough it out.