He's only four weeks old. He's had a rough old time with feeding - born with a tongue tie, learnt to latch and feed then had the tie cut and had to learn again. He's also an extremely hungry baby who needs to feed every few hours on both breasts for a long time - tends to cluster feed in the evenings for about four hours with an increasing amount of fussing. The only thing that settles him is breastfeeding.
Today he's been really unhappy with lots of high pitched cries. He struggles to latch and screams when he loses it. Feeding a lot isn't unusual for him but he is keeping the nipple in his mouth when he's not sucking, which is new for him. I've noticed he's started spitting before he cries with lots drooling and bubbling in between too.
His gums feel very hard and looking in, he has something like white buds erupting at the top. (Pic attached!) It's too early for him to get teeth, surely? His dad got them at six weeks.
Agree with Blue. It's possible (though v unusual) for a baby to get teeth at 4 weeks). But I found with my DC1 that I thought for months he was on the verge of getting a tooth (from the kind of symptoms you describe) and it didn't actually happen until he was 9 months!