Hi, my first pregnancy & my 2nd have been almost identical except for the morning sickness. My first I had a little girl and I'm expecting a son in July. I had severe sickness with my first the whole pregnancy and this time it has eased at 20 weeks. Apart from that everything else is the same so I don't think you can tell based on heartbeats and weight gain. With my first I didn't show until I was 7 months and I haven't gained much weight this time either. I craved milk with my first from Week 5 and morning sickness affects everyone differently based on your hormones. If you really want to know you can pay to have a private scan done without hubby.