You need to ask this question to a physician. If you have reasons to worry, ask many. This is too serious a question to be answered on such a "random answer" web site...
If there is no heartbeat by 8 weeks then you should schedule an ultrasound to make sure the baby is healthy. If you already had an ultrasound then chances are you might miscarry. There is no medical...
Missed period (or possibly 2 missed periods) Positive pregnancy test
Feeling sick/actually being sick
Certain smells/food/colours making you feel/be sick
Food cravings
Increased OR decreased...
Morning sickness... Also eating foods you wouldn't usually eat (Ex. Pickles and ranch dressing) I know I may not have it all, wiki pregnancy and all the symptoms should pop up.