I have the odd weed here and there also coming through. Is there anything I can buy to kill the weeds and also feed the baby grass? A weed and feed that won't harm the new grass?

I sowed the seed 3 weeks ago and it's all coming through beautifully (loads of prep went in!) but i don't want to be standing on the baby grass to hoe the weeds out. Or should I just get on there quickly and hoe them?

thanks