8 weeks pregnant- light spotting/diarrhea

Hi ladies, I’m currently 8 weeks pregnant, I do see my doctor today. But yesterday morning around 4:00am my SO and I had sex, I didn’t notice anything unusual. I went to work and wasn’t feeling my best at work. But when I got home last night around 9:00pm and went to the bathroom I had a very light spotting when I wiped. Now this morning it’s a little more, which is what is in the picture. I’m really scared because 2 weeks ago when I had an US my doctor said he was still concerned about my pregnancy bc the heartbeat was there but it was extremely slow. Also- before I found out I was pregnant I had spotting and cramping, and when I was 3 weeks I had sex and full on bleed and it lightened up. & now this.

& also I have had diarrhea for 3 days now... I did eat half a whole watermelon within these days, but also went to my cousin house and I guess they had diarrhea and I didn’t know.

So I’m just scared and curious do you guys think I should be worried????