A single pregnant female can cause an infestation of more than 5,000 bed bugs within a six-month period.
Hatched eggs are called nymphs. Nymphs can begin blood feeding as soon as they hatch. After hatching the newly born nymph will be able to detect the breath of any person or persons asleep even 50 meters or more from where it hatches. So it will crawl and climb towards the source of that because it instinctively knows that is a source of food.
Now that it knows your sleeping place it will climb up or occasionally drop down into your bed and bite you for its first blood meal and it takes it about 3 minutes to complete that meal. You are very unlikely to feel anything when it is having its meal because it injects a kind of anaesthetic into you which makes you go numb. After its first meal the nymph will find a hiding place such as in a crevice inside your mattress and come back for more meals on subsequent nights. So now an infestation of your bed is progressing, probably without you knowing.
So considering it usually takes 6-8 weeks before you realize you have bed bugs, it’s likely you will have the beginnings of an infestation with many nymphs already hiding in your belongings.
This is why you need to act as soon as possible when you discover you have bed bugs. Also remember DO NOT SPRAY ANYTHING. This will only cause them to spread through out your property.