Sometimes base on last month period isnt so accurate as previously when i found out i was pregnant, suppose to be 7 weeks but when doc scan only 5 weeks and no baby. Best to scan around 8 weeks cause by then can already see foetus and heartbeat. However if this early, you might want to get hcg blood test, it will show your hcg level and doc will advise which week you are in. They will advise accordingly. Do lookout for any spotting, blood or abdominal pain in the mean time. May Allah bless you with a baby soon 💕
You could have had a late conception and so the dating is inaccurate. If your pregnancy test is those ones that measure hcg levels (those with 2 lines, not the digital ones that show smiley face) and if you can get them for cheap (those strips from shopee or something), you can test them every day. If your hcg levels are at least stagnant or increasing (line getting darker) then you should be fine. If your hcg levels are decreasing, then it may indicate a miscarriage.