i had been on the shot for about a month before having unprotected sex. it has now been another month since i had sex and i should be starting my period soon. im very worried, however, because im showing pregnancy symptoms i.e. my breasts are sore, lower back pain, nausea, headache, etc. could this be because its time for my period? or related to the shot in some way? im extremely scared. any feedback would be appreciated.