Symptoms are a really poor judge of how a pregnancy is going. I am proof. I had every symptom in the book x 100! I was sick as a dog from week 5 up until the day I had my D&C (13 weeks). I was throwing up that same morning heading into surgery. I was achy and super tired. Couldn't stay awake past 8 p.m. By the symptoms I experienced I would have thought I was having the healthiest baby ever!
Good Luck to you and be glad you don't have many symptoms!
It's not uncommon for symptoms to come and go.
I was the same as you, my boobs were a bit sore to start With n had the cramps n everything tapered off, but then the morning sickness started at 8 weeks :/ did not enjoy, I'm now 21 weeks pregnant n the only way I can tell I am actually carrying a baby is when the little one is moving around.
I'd go to your doctor and ask him/ her to test your hormone level cos sometimes it's not alway a good sign, but at the same time not always a bad one either, hope everything is ok x