We have no literary evidence (which, honestly, is all we've got, as the archaeology is inconclusive at this point, and so far as I know, we have no osteoarchaeological analysis of women buried with weapons to see if they have wounds or deformities associated with combat) to suggest that women fought alongside men in the 8th-11th centuries in Scandinavia. There are förnaldursögur which tell of women warriors, but those are entirely fictional and should not be used to support the idea.

Freydís Eíriksdóttír famously scared off the skrælingar who attacked her campsite in Vínland, but that, I don't think, is sufficient evidence for warrior women in a non-legendary context.

It's possible, but not guaranteed. The concept of a "shieldmaiden" was a more common literary and mythical concept, but we have no 100% proof it was a reality for women to fight as part of an invading force (keep in mind when defending it's more likely that women would get involved in the fray). They are often mentioned in sagas such as Hervarar saga ok Heiðreks and in Gesta Danorum. The Byzantine historian John Skylitzes records that women fought in battle when Sviatoslav I of Kiev attacked the Byzantines in Bulgaria in 971. When the Varangians had suffered a devastating defeat, the victors were stunned at discovering armed women among the fallen warriors. In The Greenland Saga, Leif Erikssen's pregnant sister is said to have entered the battle bare-breasted. This sounds a little unlikely, so most assume that most sources are either mythical in nature, or are depicting the vikings as barbarians and having women fighting among them propagated this stereotype. It's not impossible that there were women fighting though, just something to keep in mind while reading.

This very small study suggests that women migrated with the male vikings. http://onlinelibrary.wiley.com/doi/10.1111/j.1468-0254.2011.00323.x/abstract

Some people inferred that earlier excavations containing remains buried with swords may have misidentified women as men and hypothesized that these possibly misidentified remains could have been female warriors. Unfortunately the above study had a very small sample size and I'm not aware of other published studies in this area since then. We would need further study in this area as described by Eyestache.