Welcome to Singapore and congrats on your pregnancy!
My pregnancy symptoms started at around 3 weeks and they were very similar to symptoms that my period was coming. I felt tired, hungry all the time, and very irritable. I did feel very tired too but I thought it because I wasn't getting enough sleep. Only when I tested positive after I missed my period, then did I realize I'm pregnant!
Some women get morning sickness, while others dont't. So count your lucky stars if you sail through the pregnancy without a taste of it. It's horrible!
Usually the first OB visit will occur at around 6 weeks as anything before that will not be detectable on the ultrasound scan. You should be able to see your baby's heartbeat, but sometimes you may not get to see if until a couple of weeks later.
The OB will ask you questions on your family's health history to look out for high blood pressure, diabetes, and any other personal health problems you may have. You will also get some folic acid and vitamins to supplement the baby's growth.
Hope this helps!