Could I have bedbugs even if there is no obvious changes in my skin?

Yes. Bed bug bites may cause no symptoms or signs in some people. When there is a reaction, it may not show until several days after the bed bug has bitten. It can cause pink, swollen, itchy lesions on the skin. What can be telltale is when there is a linear track of lesions from sequential feedings – but that does not always occur.
Yes. Bedbugs do not always leave marks.If there is itching on arms and legs in morning check bed for any evidence of blood specks on seam of mattress.