Uy, I really think you need to call your OB right away or go to your clinic, this is something they need to explain to you properly and maybe follow up with another ultrasound, kaya hindi mo dapat maghintay.
At 5 weeks, sometimes the embryo ay hindi pa talaga nakikita clearly sa ultrasound, pero your doctor lang ang makakasabi ng tama based sa your results at dating ng pregnancy, kaya please don't worry alone, go see them agad. A few of us moms went through uncertain early scans din, and ang kailangan talaga ay professional follow-up, not guessing. Sending you a hug, you've got this.