Still very early to come to any conclusive diagnosis. You may try an ultrasound, but it will be difficult to detect a sac which is less than 5 weeks. Meanwhile, just wait and relax, you're perhaps getting a bit anxious, which is normal due to your past history of pregnancy loss. You can get a serum B hcg test, which can provide more information about the status of your pregnancy
Next Steps
Ultrasound (obstetric) after 5 weeks from first date of the recent period.