Jangan risau sangat lah mama, at 28 weeks kadang-kadang tendangan memang boleh terasa kurang kalau placenta positioned di depan atau kalau baby tengah tidur, a few of my mum friends actually went through the same worry and turned out fine je. Since your scan yesterday showed baby is moving and heart is good, that's the reassuring part, tapi kalau you want extra peace of mind boleh lah call your clinic or midwife just to confirm everything, they won't mind!