Constipated?

So my baby is exclusively formula fed. She’s been this way since she was about 2 weeks old. She’s 8 weeks 2 days now. She usually poops about once a day to once every two days but it’s always a huge blowout of very soft poop. It’s just always been that way. Kind of like pudding. In the last day she pooped once and it was more like clay. We haven’t changed anything. Is it possible that the formula could cause constipation out of nowhere? I watch her try to poop. She strains but nothing comes out. The only other thing I have to add is I think she may be an early teether bc she is drooling like crazy and trying to suck on everything. Is that a possible cause? Ftm, thanks in advance.