Light spotting & cramping

I got a positive test on 10/10 & again yesterday. Yesterday afternoon I began cramping with some light spotting. This morning my test is stronger (bottom test). Could this be implantation bleeding or the beginning of a mc? I bled on/off until week 9 in my last pregnancy & then was put on progesterone. This is my 5th pregnancy in 2 years, & have had 1 successful pregnancy.