No problem. Those might work for you. Feeling the baby kicks will help reassure you too
Get a dobbler if you're unsure. They have them on eBay and they come with he jelly and all.
Guess it depends on each person. I'm 18 weeks & since I had a miscarriage last July I need alittle reassurance.
I ordered one last week when I turned 18 weeks and didn't find it at first but then I found it perfect and easily the second day.