over working my body?

GouletB

I was running between 5.5 and 7 miles at 2% then lifting (I can't work out everyday) and for the past couple months I've been about 120-123lbs. This last week I did about 3 miles combined with level 2 of 30day shred. I did that two times and one day with a long run and I lost about 5lbs last week!!!!! What is going on!!!!??!!