What Causes Brown Vaginal Discharge During Pregnancy?

Hi, I am around six weeks pregnant. As I knew intercourse is dangerous during pregnancy I masturbatd yesterday only external. After that I went to sleep for about two hrs. After waking up i went to toilet and notice while wiping with toilet paper some blood and also on my gown some stains. But very soon it started to become light brownish when I next went to the toilet after 10mins. I m not bleeding after that at all and there is hardly any brown discharge now. I didn t cramp nor I had pain. I m fine now. But very worried if I have miscarried my first child.please advice thanks