hcg plz help

Rania
Hi ladies. 
I found out I was pregnant two days ago. A little background for you. My period is usually 33-34 days. However I ovulated on CD 25 (approximately) since me and hubby only had intercourse that day and I fell pregnant. Since I ovulated late that would mean I implanted late as well.
Well!! I took my blood yesterday and they told me my HCG was only 47, they seemed concerned as it is low. I am going in tomorrow for another one to see my levels. 
Has anyone ovulated so Late and fell pregnant. I thought I was roughly 4 weeks pregnant, but now I am not so sure. 
Anyone with tips or experience I would love to hear from you. I was having a great birthday until I got this phone call. 
Thanks in advance