my cat keeps massaging my belly

My cat keeps massaging my belly and is always laying next to my belly. Does he know I might be pregnant? I'm 4 day late according to this app. But I also have another <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a> which says I'm 9 days late. I already took a pregnancy test and it came out negative !