Help please

an

My period was due on 15th June and I been blessed to be pregnant, I checked on 19 th and it was positive, went to doctors and check urine HCG report and it was positive too🙏 today I went to see specialist doctor to get further vitamins and everything and doctor done ultra sound scan today and he said still can’t see sack yet , he done Transvaginal Ultrasound as well but can’t seen anything , is it normal to not to see anything clear on ultrasound for 5 weeks ? Is it too early to see anything ? Your help much appreciate 🙏