Only 16....

So in the last 3 weeks I've had sex 3 times, and I'm 3 days late for my period. We use condoms everytime, they never came off or ripped. Been having pms symptoms- sore breasts, cramping, highly emotional and a high sex-drive, and minimal nausea. I don't want to have a baby but I don't know if I could handle an abortion... I can't really afford to get an early response pregnancy test.. Is it the best idea to get one or just wait until my period is at least a week late or see if it comes within the next four days ?