Finally felt baby kick!!!

2 days ago I finally felt my baby kick! I was 15 weeks 3 days. I was reaching up to hang a curtain and got a kick right under my belly button! Actually startled me lol. Then yesterday I was laying on my back watching tv and raised up you turn over and got a kick to the left side of my belly. I made my hubby jump cuz I kinda yelled ahh! it scared me lol. Now I keep trying to feel it and feel no kicks lol it's only when I'm not expecting it. I do think I can tell when the baby is moving around though..I just get this feeling like little fishies are swimming around inside me or something. I am so excited to start feeling movement daily. Anyone else feeling their babies move or kick yet? This is my 7 th pregnancy but 6 th child. I worry constantly about this baby though because for one I smoke and 2 , I am 38 years old now so chance of problems increase. This is definitely my last one. Too much stress! Feeling the baby move is such a relief. I also have a fetal doppler and have heard heartbeat since 8 weeks but I swear there is 2 heartbeats!! The rhythms are totally different and number of beats are different as well. I've only had one ultrasound so far and only seen one but it was an older portable machine and doctor admitted she wasn't very experienced with ultrasounds! I didn't feel like she really looked very hard. Im just wondering if one could have been hiding behind the other. On screen my baby was facing up...she turned it off then said oh u need a pic and just stuck it on my belly randomly and snapped a pic but the pic looks like baby is facing down... I should have another one at hospital around 20 weeks or maybe sooner because I was measuring 16 weeks at only 13 weeks at my last visit. All this uncertainty is making me crazy!