Spotting 4 days before periods

I have been married 8 weeks . I am due to start my periods in 4 days, we did make love during my ovulation dates. I have pink/brown watery spotting for about 2-3 hours today then stopped but started again this morning, very very light - I have heavy periods usually and I’m usually in bed with the symptoms! The only symptoms I currently have is lower abdominal cramps and lower back pain and Right leg very much like sciatica pain, other than that I’m up and on the go! What could this be?