Could Vaginal Spotting During Pregnancy Be Symptom Of Miscarriage?

I am 35 got one boy child 10 year old,had 2 miscarriages in last 5 years, one when I was 29 year old another when i was 34. now I am pregnant with 5 weeks but am having spotting. i have no cramps as such but i have spotting now and then. Dr gave me Trenexa again I saw brown discharge while taking bath. Am worried....