Hard to describe. I will try though.
About 6 weeks ago (around 5 months PG, 20w or so), I started feeling baby - but it was like intense butterflies in my stomach for a few minutes at a time. Only felt it now and then, like after something sugary. It was very sporatic and unpredictable.
Over the last 4 weeks or so, I have felt her "thumping" in there. Started feeling thumps about 22w. In the beginning, it was like little taps from the inside, right behind my bellybutton. Think of how it feels to have someone tap you on the arm. This is how it felt, but against my stomach from the INSIDE.
In the last 2 week (around 24w, 6 months PG) the thumps have been getting harder and more frequent. It started feeling less like taps, and more like someone "flicking" you ..... make an 'O' with your thumb and pointer finger and then 'flick' yourself with the pointer finger. Started lightly, now getting more insistent!
The thumps started behind bellybutton, but now have moved to mostly the left side (I think her feet are there) and sometimes on the right (I think those are her arms/hands). The feelings are right along your oblique muscles in the abs.
Her kicks/punches are becoming harder and more frequent. They are slowly feeling less like 'flicks' with a pointer finger and more like 'flicks' with a hand. The feeling is becoming bigger and taking up more space. The other night I was laying on my left side in bed watching TV and she poked something internal so hard I jumped up to almost sitting position. I think she kicked a kidney, lol.
She mostly seems to kick/punch OUT, *not* towards my diaphragm (up), my pevis (down) or my spine (back). So nothing HURTS, it just feels weird, good weird though. I know these movements are coming, I have a feeling she is going to be that baby that wedges a foot inbetween my ribs...... *sigh*
She also has more active times now..... I used to only feel her in the evening (between 8-9pm) when I was in bed, laying still. Now I feel her throughout the day, but her MOST active times are in the late afternoon right now .... 2pm and 5pm. SHe has NOT woken me up at night yet, although I am sure that is coming. I am hoping she is like Mommy......LOVES sleep.
It is by far the coolest thing to feel.