Is that a bed bug?

No, no bedbug, but an Australian rug that belongs to the Speckkäfer family.

https://arthropodafotos.de/dbsp.php?lang=deu&sc=1&ta=t_35_coleo_pol_derm&sci=Anthrenocerus&scisp=australis

https://www.google.de/search?q=anthrenocerus+australis&source=lnms&tbm=isch&sa=X&ved=2ahUKEwi9qO7wisbvAhUB3KQKHdqNDVAQ_AUoAXoECAEQAwUMbiw=1196&bih=661&dpr=136

But whether exactly the one or another from this family remains quite the same, because all are among the material damages in the household.

Their larvae feed on textiles, wool fabrics, mattresses, upholstery, feathers, carpets and some more – making them unusable for us.

When you discover them more in the house, you should look for where to find more beetles and larvae.

Here targeted:

• in bed, bed frame, mattress, pillows and blankets
• on and under carpets, also edges and strips
• in the wardrobe, also in the edges, corners and ridges
• on garments, furs and other woolen fabrics
• Dry food for pets

Wash infested at at least 60° or freeze for a few days.Suck very well, here also the edges and strips do not forget, because these larvae are masters in hiding.

More tips here:

https://www.ungeziefer-und-schaedlinge.de/teppichkaefer-bekaempf.php

More pictures of the larvae:

https://www.google.de/search?q=Anthrenocerus+australis+larvae&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiuieGH_dPxAhXahv0Hck5CBQ_AUoAXoECAIQAw&biw=1315&bih=710